PHP/MySQL三日通(2)webhunter
时间：2007-02-17 来源：PHP爱好者
PHP/MySQL三日通－第二天
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原作者：Graeme Merrall
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目录
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PHP/MySQL教程－第一天
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一、PHP/MySQL简介
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二、安装MySQL
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三、安装PHP
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四、第一个脚本
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五、装载数据库
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六、测试
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PHP/MySQL教程－第二天
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一、while循环
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二、if-else
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三、第一个程序脚本
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四、向服务器发送数据
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五、修改数据
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六、完整的程序
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PHP/MySQL教程－第三天
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一、基本函数
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二、数据校验
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三、处理常规表达式
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四、简便方法
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五、进阶技巧
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一、 while循环
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在这一课里，我们将会继续深入下去，使用PHP和MySQL来写出一些简单而有
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用的页面。我们从昨天创建的数据库开始，显示库中的数据，但是会再稍微加以
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润色。
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首先，我们用下面的代码来查询数据库内容。
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<html>
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<body>
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<?php
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$db = mysql_connect("localhost", "root");
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mysql_select_db("mydb",$db);
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$result = mysql_query("SELECT * FROM employees",$db);
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echo "<table border=1>n";
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echo "<tr><td>姓名</td><td>职位</td></tr>n";
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while ($myrow = mysql_fetch_row($result)) {
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printf("<tr><td>%s %s</td><td>%s</td></tr>n", $myro
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w[1], $myrow[2], $myrow[3]);
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}
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echo "</table>n";
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?>
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</body>
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</html>
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您可能已经注意到，我们在这个程序里加进了一些新东西。最明显的是whil
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e()循环。该循环是说，只要数据库里还有记录可读（使用mysql_fetch_row()函
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数），那就把该记录赋给变量$myrow，然后执行大括号（{}）内的指令。仔细看
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一下这里，这部分是比较重要的。
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我们应该注意一下mysql_fetch_row()函数。这里有一点小问题，它返回的是
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一个数组，必须以数组下标来访问其中的某个字段。第一个字段下标为0，第二个
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是1，依此类推。在执行某些复杂查询时，这么做简直实在是太烦琐了。
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现在我们更仔细地研究一下循环过程。程序前几行我们在第一课的例子中已
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经看到过了。然后，在while()循环中，我们从查询结果中读取一条记录并把该记
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录赋给数组$myrow。接着，我们用printf函数把数据中的内容显示在屏幕上。随
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后，循环反复执行，读取下一条记录赋给$myrow。这样继续下去，直到所有记录
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都已被读取完为止。
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使用while()循环的一个好处是，如果数据库查询没有返回任何记录，那您也
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不会收到错误信息。在刚执行循环语句时，循环条件就不满足，不会有任何数据
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赋给$myrow，程序就直接往下运行了。
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但是如果查询未返回任何数据，我们怎么让用户知道这一点呢？我们也许该
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提供点儿相关的消息给用户吧。这是可以做到的，下面我们就看看怎么做。>>
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二、 if-else
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请看下面的程序。
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<html>
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<body>
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<?php
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$db = mysql_connect("localhost", "root");
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mysql_select_db("mydb",$db);
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$result = mysql_query("SELECT * FROM employees",$db);
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if ($myrow = mysql_fetch_array($result)) {
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echo "<table border=1>n";
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echo "<tr><td>姓名</td><td>住址</td></tr>n";
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do {
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printf("<tr><td>%s %s</td><td>%s</tr>n", $myrow["first"],
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$myrow["last"], $myrow["address"]);
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} while ($myrow = mysql_fetch_array($result));
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echo "</table>n";
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} else {
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echo "对不起，没有找到记录！";
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}
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?>
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</body>
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</html>
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这段程序中包含有不少新内容，不过这些内容都相当简单。首先是mysql_fe
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tch_array()函数。该函数与mysql_fetch_row()十分相近，只有一点不同：使用
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这个函数时，我们可以通过字段名而不是数组下标来访问它返回的字段，比如$m
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yrow["first"]。这样我们就可以省不少力气了。另外，程序中还加进了do/whil
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e循环和if-else条件判定语句。
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if-else条件判定语句的含意是，如果我们成功地把一条记录赋给了$myrow变
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量，那就继续；否则，就跳到else部分，执行那里的指令。
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do/while循环是我们在上页中用户的while()循环的一个变体。我们要用到d
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o/while的原因是：在最初的if语句中，我们已经把查询返回的第一条记录赋给变
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量$myrow了。如果这时我们执行一般的while循环（比如，while ($myrow = mys
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ql_fetch_row($result)），那我们就会把第二条记录赋给$myrow，而第一条记录
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就被冲掉了。但是do/while循环可以让我们执行一次循环体内容之后再来判定循
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环条件。因此，我们就不会不小心漏掉第一条记录了。
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最后，如果查询结果没有任何记录的话，程序就会执行包含在else{}部分的
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那些语句。如果您想看到这部分程序的执行情况，可以把SQL语句改为SELECT *
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FROM employees WHERE id=6，或改成其他形式，使得查询结果中没有任何记录。
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下面我们来扩充一下循环if-else 代码，使得页面内容更加丰富。相信您会
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喜欢的。>>
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三、 第一个程序脚本
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我们刚刚学到了循环语句，下面我们将在一个更加实际一点的例子中看看如
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何运用它。但是在这之前，您应该知道如何处理Web表格、查询参数串，以及表单
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的GET方法和POST方法。不久之前我们刚刚有文章介绍这部分内容，您如果对这一
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部分还不太熟悉的话可以看看那篇文章。
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现在，我们要处理查询参数串，正如您所知道的，有三种方法可以把参数内
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容写入到查询参数串中。第一种是在表格中使用GET方法；第二种是在浏览器的地
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址栏中输入网址时直接加上查询参数；第三种是把查询参数串嵌入到网页的超链
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接中，使得超链接的内容象下面这样：<a href="http://my_machine/mypage.ph
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p3?id=1">。我们现在要用到最后这一种方法。
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一开始，我们再来查询我们的数据库，列出员工姓名。看看下面的程序，其
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中大部分内容我们都已经很熟悉了。
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<html>
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<body>
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<?php
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$db = mysql_connect("localhost", "root");
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mysql_select_db("mydb",$db);
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$result = mysql_query("SELECT * FROM employees",$db);
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if ($myrow = mysql_fetch_array($result)) {
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do {
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printf("<a href="%s?id=%s">%s %s</a><br>n",
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$PATH_INFO, $myrow["id"], $myrow["first"], $myrow["last"]);
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} while ($myrow = mysql_fetch_array($result));
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} else {
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echo "对不起，没有找到记录！";
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}
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?>
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</body>
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</html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
这里没什么特别的，只是printf函数有些不同。那我们就来仔细研究一下。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
首先要注意的是，所有的引号前面都有一个反斜杠。这个反斜杠告诉PHP直接
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
显示后面的字符，而不能把后面的字符当作程序代码来处理。另外要注意变量$P
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ATH_INFO的用法。该变量在所用程序中都可以访问，是用来保存程序自身的名称
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与目录位置的。我们之所以用到它是因为要在页面中再调用这个程序本身。使用
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$PATH_INFO，我们可以做到，即使程序被挪到其他目录，甚至是其他机器上时，
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我们也能保证正确地调用到这个程序。
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
正如我刚才提到的，程序所生成的网页，其中包含的超链接会再次调用程序
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本身。不过，再次调用时，会加入一些查询参数。
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PHP见到查询参数串中包含有“名字=值”这样的成对格式时，会作一些特别
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的处理。它会自动生成一个变量，变量名称与取值都与查询参数串中所给定的名
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称和取值相同。这一功能使得我们可以在程序中判断出是第一次执行本程序还是
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第二次。我们所要做的只是问问PHP$id这个变量是否存在。
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当我知道这个问题的答案后，我可以在第二次调用程序时显示一些不同的结
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果出来。请看：
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<html>
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<body>
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<?php
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$db = mysql_connect("localhost", "root");
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mysql_select_db("mydb",$db);
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// display individual record
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// 显示单条记录内容
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if ($id) {
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$result = mysql_query("SELECT * FROM employees WHERE id=$id",$db);
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$myrow = mysql_fetch_array($result);
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printf("名: %sn<br>", $myrow["first"]);
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printf("姓: %sn<br>", $myrow["last"]);
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printf("住址: %sn<br>", $myrow["address"]);
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printf("职位: %sn<br>", $myrow["position"]);
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} else {
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// show employee list
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// 显示员工列表
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$result = mysql_query("SELECT * FROM employees",$db);
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if ($myrow = mysql_fetch_array($result)) {
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// display list if there are records to display
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// 如果有记录，则显示列表
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do {
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printf("<a href="%s?id=%s">%s %s</a><br>n", $PATH_INFO,
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$myrow["id"], $myrow["first"], $myrow["last"]);
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} while ($myrow = mysql_fetch_array($result));
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} else {
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// no records to display
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// 没有记录可显示
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echo "对不起，没有找到记录！";
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}
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}
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?>
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</body>
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</html>
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程序开始变得复杂了，所以我在这里面加了注释，来解释一下到底发生了什
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么。您可以用//加入单行注释，或者用/*和*/来括住大段的注释。
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到这里，我们已经学会了第一个真正有用的PHP/MySQL脚本程序！现在，我们
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要看看怎样把Web表格加进来，并且向数据库发送数据。>>
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四、 向服务器发送数据
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现在我们从数据库读取数据已经没有太多困难了。但是怎么反过来向数据库
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
发送数据呢？其实这不是PHP的问题。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
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首选，我们创建一个带有简单表格的网页。
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<html>
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<body>
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<form method="post" action="<?php echo $PATH_INFO?>">
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名：<input type="Text" name="first"><br>
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姓：<input type="Text" name="last"><br>
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住址：<input type="Text" name="address"><br>
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
职位：<input type="Text" name="position"><br>
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<input type="Submit" name="submit" value="输入信息">
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</form>
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</body>
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
同样要注意$PATH_INFO的用法。就象我在第一课里讲到的，您可以在HTML代
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
码中的任意位置使用PHP。您也会注意到，表格中的每一个元素都对应着数据库中
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
的一个字段。这种对应关系并不是必须的，这么做只是更直观一些，便于您以后
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
理解这些代码。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
还要注意的是，我在Submit按钮中加入了name属性。这样我在程序中可以试
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
探$submit变量是否存在。于是，当网页被再次调用时，我就会知道调用页面时是
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
否已经填写了表格。
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
我应该指出，您不一定要把上面的网页内容写到PHP程序中，再返过来调用程
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
序本身。您完全可以把显示表格的网页和处理表格的程序分开放在两个网页、三
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
个网页甚至更多网页中，悉听尊便。放在一个文件中只是可以使内容更加紧凑而
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
已。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
那好，我们现在加入一些代码，来检查用户在表格中输入的内容。我会把用
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$HTTP_POST_VARS把所有查询参数变量都显示出来，这只不过是为了证明PHP确实
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
把所有变量都传给了程序。这种方法是一个很有用的调试手段。如果您要想看全
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
部的变量，可以用$GLOBALS。
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
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<html>
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<body>
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<?php
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if ($submit) {
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// 处理表格输入
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
while (list($name, $value) = each($HTTP_POST_VARS)) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
echo "$name = $value<br>n";
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
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} else{
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// 显示表格
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?>
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<form method="post" action="<?php echo $PATH_INFO?>">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
名：<input type="Text" name="first"><br>
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
姓：<input type="Text" name="last"><br>
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
住址：<input type="Text" name="address"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
职位：<input type="Text" name="position"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<input type="Submit" name="submit" value="输入信息">
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</form>
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} // end if，if结束
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
程序现在运行正常，那我们现在就可以取到表格输入的内容，并把它们发送
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
给数据库。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
if ($submit) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 处理表格输入
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$db = mysql_connect("localhost", "root");
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
mysql_select_db("mydb",$db);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$sql = "INSERT INTO employees (first,last,address,position)
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
VALUES ('$first','$last','$address','$position')";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query($sql);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
echo "Thank you! Information entered.n";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} else{
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 显示表格内容
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<form method="post" action="<?php echo $PATH_INFO?>">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
名：<input type="Text" name="first"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
姓：<input type="Text" name="last"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
住址：<input type="Text" name="address"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
职位：<input type="Text" name="position"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<input type="Submit" name="submit" value="输入信息">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</form>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} // end if，if结束
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
您现在已经向数据库中插入数据了。不过还有很多完善的工作要做。如果用
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
户没有填写某一栏怎么办？在需要填入数字的地方填了文字怎么办？或者填错了
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
怎么办？
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
别担心。我们一步一步来。>>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
五、修改数据
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
在个教程中，我都把要执行的SQL语句放到一个变量（$sql）中，然后才用m
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
ysql_query()来执行数据库查询。在调试时这是很有用的。如果程序出了什么问
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
题，您随时可以把SQL语句的内容显示出来，检查其中的语法错误。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
我们已经学习了如何把数据插入到数据库中。现在我们来学习如何修改数据
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
库中已有的记录。数据的编辑包括两部分：数据显示和通过表格输入把数据返回
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
给数据库，这两部分我们前面都已经讲到了。然而，数据编辑还是有一点点不同
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
，我们必须先在表格中显示出相关的数据。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
首先，我们回过头再看看第一课的程序代码，在网页中显示员工姓名。但是
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
这次，我们要把数据显示在表格中。程序看起来象下面这样：
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$db = mysql_connect("localhost", "root");
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
mysql_select_db("mydb",$db);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
if ($id) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 查询数据库
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$sql = "SELECT * FROM employees WHERE id=$id";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query($sql);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow = mysql_fetch_array($result);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<form method="post" action="<?php echo $PATH_INFO?>">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<input type=hidden name="id" value="<?php echo $myrow["id"] ?>">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
名：<input type="Text" name="first" value="<?php echo
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["first"] ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
姓：<input type="Text" name="last" value="<?php echo
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["last"] ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
住址：<input type="Text" name="address" value="<?php echo
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["address"] ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
职位：<input type="Text" name="position" value="<?php echo
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["position"] ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<input type="Submit" name="submit" value="输入信息">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</form>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} else {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 显示员工列表
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query("SELECT * FROM employees",$db);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
while ($myrow = mysql_fetch_array($result)) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
printf("<a href="%s?id=%s">%s %s</a><br>n", $PATH_INFO,
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["id"], $myrow["first"], $myrow["last"]);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
我们刚才是把字段内容写入到相应表格元素中的value属性里，这是相应简单
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
的。我们再往前进一步，使程序可以把用户修改过的内容写回数据库去。同样，
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
我们通过Submit按钮来判断是否处理表格输入内容。还要注意，我们用的SQL语句
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
稍稍有些不同。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$db = mysql_connect("localhost", "root");
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
mysql_select_db("mydb",$db);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
if ($id) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
if ($submit) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$sql = "UPDATE employees SET first='$first',last='$last',
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
address='$address',position='$position' WHERE id=$id";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query($sql);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
echo "谢谢！数据更改完成n";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} else {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 查询数据库
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$sql = "SELECT * FROM employees WHERE id=$id";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query($sql);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow = mysql_fetch_array($result);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<form method="post" action="<?php echo $PATH_INFO?>">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<input type=hidden name="id" value="<?php echo $myrow["id"] ?>">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
名：<input type="Text" name="first" value="<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
echo $myrow["first"] ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
姓：<input type="Text" name="last" value="<?php echo
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["last"] ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
住址：<input type="Text" name="address" value="<?php echo
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["address"] ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
职位：<input type="Text" name="position" value="<?php echo
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["position"] ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<input type="Submit" name="submit" value="输入信息">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</form>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} else {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 显示员工列表
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query("SELECT * FROM employees",$db);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
while ($myrow = mysql_fetch_array($result)) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
printf("<a href="%s?id=%s">%s %s</a><br>n", $PATH_INFO,
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["id"], $myrow["first"], $myrow["last"]);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
就是这样。在这个程序中已经包含了我们学过所大多数特性。您也已经看到
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
，我们在一个if()条件判别语句中又加了一个if()语句，来检查多重条件。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
下面，我们要把所有东西全都加在一起，写出一个很好的程序来。>>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
六、完整的程序
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
在本课结束前，我们要把所有东西加入到一个程序中，使它具有增加、编辑修改
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
、删除记录的功能。这是前面所有内容的一个延伸，也可以作为极好的复习方法
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
。看看下面的程序。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$db = mysql_connect("localhost", "root");
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
mysql_select_db("mydb",$db);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
if ($submit) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 如果没有ID，则我们是在增加记录，否则我们是在修改记录
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
if ($id) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$sql = "UPDATE employees SET first='$first',last='$last',
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
address='$address',position='$position' WHERE id=$id";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} else {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$sql = "INSERT INTO employees (first,last,address,position)
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
VALUES ('$first','$last','$address','$position')";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 向数据库发出SQL命令
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query($sql);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
echo "记录修改成功！<p>";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} elseif ($delete) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 删除一条记录
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$sql = "DELETE FROM employees WHERE id=$id";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query($sql);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
echo "记录删除成功！<p>";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} else {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 如果我们还没有按submit按钮，那么执行下面这部分程序
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
if (!$id) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 如果不是修改状态，则显示员工列表
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query("SELECT * FROM employees",$db);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
while ($myrow = mysql_fetch_array($result)) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
printf("<a href="%s?id=%s">%s %s</a> n",
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$PATH_INFO, $myrow["id"], $myrow["first"], $myrow["last"]);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
printf("<a href="%s?id=%s&delete=yes">(DELETE)</a><
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
br>", $PATH_INFO, $myrow["id"]);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<P>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<a href="<?php echo $PATH_INFO?>">ADD A RECORD</a>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<P>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<form method="post" action="<?php echo $PATH_INFO?>">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
if ($id) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 我们是在编辑修改状态，因些选择一条记录
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$sql = "SELECT * FROM employees WHERE id=$id";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query($sql);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow = mysql_fetch_array($result);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$id = $myrow["id"];
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$first = $myrow["first"];
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$last = $myrow["last"];
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$address = $myrow["address"];
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$position = $myrow["position"];
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 显示id，供用户编辑修改
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<input type=hidden name="id" value="<?php echo $id ?>">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
名：<input type="Text" name="first" value="<?php echo $first ?>"><br
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
姓：<input type="Text" name="last" value="<?php echo $last ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
住址：<input type="Text" name="address" value="<?php echo $address ?
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
职位：<input type="Text" name="position" value="<?php echo $position
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<input type="Submit" name="submit" value="输入信息">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</form>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<`/html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
这段程序看起来很复杂，但实际上并不难。程序主要有三个部分。第一个if
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
()语句检查我们是否已经按下了那个“输入信息”的数据提交按钮。如果是，程
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
序再检查$id是否存在。如果不存在，那我们就是在增加记录状态，否则，我们是
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
在修改记录状态。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
接下来我们检查变量$delete是否存在。如果存在，我们是要删除记录。注意
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
，第一个if()语句检查的是用POST方法发送来的变量，而这一次我们检查的是GE
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
T方法中传递过来的变量。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
最后，程序默认的动作是显示员工列表和表格。同样，我们要检查变量$id是
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
否存在。如果存在，我们就根据它的值检索出相应的记录显示出来。否则，我们
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
会显示一个空的表格。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
现在，我们已经把所学的东西全部都放在一个程序里头了。我们用到了whil
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
e()循环，用到了if()语句，并且执行了全部的SQL基本操作 - SELECT、INSERT、
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
UPDATE以及DELETE。另外，我们也知道如何在不同的网页之间通过URL和表格输入
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
来互相传递信息。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
在第三课里，我们要学习如何为网页增加智能化处理能力。
php爱好者站 http://www.ｐｈｐfans.net c/vc/c++/java.
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
原作者：Graeme Merrall
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
----------------------------------------------------------------------
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
----------
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
目录
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
PHP/MySQL教程－第一天
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
一、PHP/MySQL简介
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
二、安装MySQL
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
三、安装PHP
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
四、第一个脚本
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
五、装载数据库
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
六、测试
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
PHP/MySQL教程－第二天
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
一、while循环
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
二、if-else
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三、第一个程序脚本
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四、向服务器发送数据
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五、修改数据
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六、完整的程序
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PHP/MySQL教程－第三天
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一、基本函数
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二、数据校验
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三、处理常规表达式
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四、简便方法
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五、进阶技巧
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----------------------------------------------------------------------
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----------
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一、 while循环
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在这一课里，我们将会继续深入下去，使用PHP和MySQL来写出一些简单而有
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用的页面。我们从昨天创建的数据库开始，显示库中的数据，但是会再稍微加以
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润色。
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首先，我们用下面的代码来查询数据库内容。
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<html>
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<body>
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<?php
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$db = mysql_connect("localhost", "root");
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mysql_select_db("mydb",$db);
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$result = mysql_query("SELECT * FROM employees",$db);
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echo "<table border=1>n";
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echo "<tr><td>姓名</td><td>职位</td></tr>n";
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while ($myrow = mysql_fetch_row($result)) {
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printf("<tr><td>%s %s</td><td>%s</td></tr>n", $myro
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w[1], $myrow[2], $myrow[3]);
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}
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echo "</table>n";
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?>
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</body>
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</html>
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您可能已经注意到，我们在这个程序里加进了一些新东西。最明显的是whil
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e()循环。该循环是说，只要数据库里还有记录可读（使用mysql_fetch_row()函
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数），那就把该记录赋给变量$myrow，然后执行大括号（{}）内的指令。仔细看
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一下这里，这部分是比较重要的。
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我们应该注意一下mysql_fetch_row()函数。这里有一点小问题，它返回的是
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一个数组，必须以数组下标来访问其中的某个字段。第一个字段下标为0，第二个
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是1，依此类推。在执行某些复杂查询时，这么做简直实在是太烦琐了。
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现在我们更仔细地研究一下循环过程。程序前几行我们在第一课的例子中已
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经看到过了。然后，在while()循环中，我们从查询结果中读取一条记录并把该记
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录赋给数组$myrow。接着，我们用printf函数把数据中的内容显示在屏幕上。随
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后，循环反复执行，读取下一条记录赋给$myrow。这样继续下去，直到所有记录
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都已被读取完为止。
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使用while()循环的一个好处是，如果数据库查询没有返回任何记录，那您也
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不会收到错误信息。在刚执行循环语句时，循环条件就不满足，不会有任何数据
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赋给$myrow，程序就直接往下运行了。
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但是如果查询未返回任何数据，我们怎么让用户知道这一点呢？我们也许该
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提供点儿相关的消息给用户吧。这是可以做到的，下面我们就看看怎么做。>>
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二、 if-else
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请看下面的程序。
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<html>
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<body>
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<?php
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$db = mysql_connect("localhost", "root");
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mysql_select_db("mydb",$db);
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$result = mysql_query("SELECT * FROM employees",$db);
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if ($myrow = mysql_fetch_array($result)) {
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
echo "<table border=1>n";
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echo "<tr><td>姓名</td><td>住址</td></tr>n";
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do {
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printf("<tr><td>%s %s</td><td>%s</tr>n", $myrow["first"],
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$myrow["last"], $myrow["address"]);
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} while ($myrow = mysql_fetch_array($result));
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echo "</table>n";
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} else {
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echo "对不起，没有找到记录！";
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}
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?>
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</body>
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</html>
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这段程序中包含有不少新内容，不过这些内容都相当简单。首先是mysql_fe
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
tch_array()函数。该函数与mysql_fetch_row()十分相近，只有一点不同：使用
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这个函数时，我们可以通过字段名而不是数组下标来访问它返回的字段，比如$m
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
yrow["first"]。这样我们就可以省不少力气了。另外，程序中还加进了do/whil
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e循环和if-else条件判定语句。
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if-else条件判定语句的含意是，如果我们成功地把一条记录赋给了$myrow变
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量，那就继续；否则，就跳到else部分，执行那里的指令。
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do/while循环是我们在上页中用户的while()循环的一个变体。我们要用到d
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o/while的原因是：在最初的if语句中，我们已经把查询返回的第一条记录赋给变
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量$myrow了。如果这时我们执行一般的while循环（比如，while ($myrow = mys
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ql_fetch_row($result)），那我们就会把第二条记录赋给$myrow，而第一条记录
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就被冲掉了。但是do/while循环可以让我们执行一次循环体内容之后再来判定循
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环条件。因此，我们就不会不小心漏掉第一条记录了。
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最后，如果查询结果没有任何记录的话，程序就会执行包含在else{}部分的
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那些语句。如果您想看到这部分程序的执行情况，可以把SQL语句改为SELECT *
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FROM employees WHERE id=6，或改成其他形式，使得查询结果中没有任何记录。
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下面我们来扩充一下循环if-else 代码，使得页面内容更加丰富。相信您会
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喜欢的。>>
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三、 第一个程序脚本
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我们刚刚学到了循环语句，下面我们将在一个更加实际一点的例子中看看如
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何运用它。但是在这之前，您应该知道如何处理Web表格、查询参数串，以及表单
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的GET方法和POST方法。不久之前我们刚刚有文章介绍这部分内容，您如果对这一
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部分还不太熟悉的话可以看看那篇文章。
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现在，我们要处理查询参数串，正如您所知道的，有三种方法可以把参数内
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容写入到查询参数串中。第一种是在表格中使用GET方法；第二种是在浏览器的地
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
址栏中输入网址时直接加上查询参数；第三种是把查询参数串嵌入到网页的超链
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接中，使得超链接的内容象下面这样：<a href="http://my_machine/mypage.ph
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p3?id=1">。我们现在要用到最后这一种方法。
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一开始，我们再来查询我们的数据库，列出员工姓名。看看下面的程序，其
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中大部分内容我们都已经很熟悉了。
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<html>
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<body>
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<?php
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$db = mysql_connect("localhost", "root");
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mysql_select_db("mydb",$db);
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$result = mysql_query("SELECT * FROM employees",$db);
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if ($myrow = mysql_fetch_array($result)) {
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
do {
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
printf("<a href="%s?id=%s">%s %s</a><br>n",
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$PATH_INFO, $myrow["id"], $myrow["first"], $myrow["last"]);
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} while ($myrow = mysql_fetch_array($result));
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} else {
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echo "对不起，没有找到记录！";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
这里没什么特别的，只是printf函数有些不同。那我们就来仔细研究一下。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
首先要注意的是，所有的引号前面都有一个反斜杠。这个反斜杠告诉PHP直接
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
显示后面的字符，而不能把后面的字符当作程序代码来处理。另外要注意变量$P
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
ATH_INFO的用法。该变量在所用程序中都可以访问，是用来保存程序自身的名称
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
与目录位置的。我们之所以用到它是因为要在页面中再调用这个程序本身。使用
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$PATH_INFO，我们可以做到，即使程序被挪到其他目录，甚至是其他机器上时，
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
我们也能保证正确地调用到这个程序。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
正如我刚才提到的，程序所生成的网页，其中包含的超链接会再次调用程序
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
本身。不过，再次调用时，会加入一些查询参数。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
PHP见到查询参数串中包含有“名字=值”这样的成对格式时，会作一些特别
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
的处理。它会自动生成一个变量，变量名称与取值都与查询参数串中所给定的名
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
称和取值相同。这一功能使得我们可以在程序中判断出是第一次执行本程序还是
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
第二次。我们所要做的只是问问PHP$id这个变量是否存在。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
当我知道这个问题的答案后，我可以在第二次调用程序时显示一些不同的结
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
果出来。请看：
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$db = mysql_connect("localhost", "root");
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
mysql_select_db("mydb",$db);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// display individual record
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 显示单条记录内容
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
if ($id) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query("SELECT * FROM employees WHERE id=$id",$db);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
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$myrow = mysql_fetch_array($result);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
printf("名: %sn<br>", $myrow["first"]);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
printf("姓: %sn<br>", $myrow["last"]);
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
printf("住址: %sn<br>", $myrow["address"]);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
printf("职位: %sn<br>", $myrow["position"]);
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} else {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// show employee list
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 显示员工列表
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query("SELECT * FROM employees",$db);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
if ($myrow = mysql_fetch_array($result)) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// display list if there are records to display
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 如果有记录，则显示列表
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
do {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
printf("<a href="%s?id=%s">%s %s</a><br>n", $PATH_INFO,
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["id"], $myrow["first"], $myrow["last"]);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} while ($myrow = mysql_fetch_array($result));
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} else {
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// no records to display
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// 没有记录可显示
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
echo "对不起，没有找到记录！";
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
程序开始变得复杂了，所以我在这里面加了注释，来解释一下到底发生了什
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
么。您可以用//加入单行注释，或者用/*和*/来括住大段的注释。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
到这里，我们已经学会了第一个真正有用的PHP/MySQL脚本程序！现在，我们
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
要看看怎样把Web表格加进来，并且向数据库发送数据。>>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
四、 向服务器发送数据
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
现在我们从数据库读取数据已经没有太多困难了。但是怎么反过来向数据库
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
发送数据呢？其实这不是PHP的问题。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
首选，我们创建一个带有简单表格的网页。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<form method="post" action="<?php echo $PATH_INFO?>">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
名：<input type="Text" name="first"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
姓：<input type="Text" name="last"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
住址：<input type="Text" name="address"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
职位：<input type="Text" name="position"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<input type="Submit" name="submit" value="输入信息">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</form>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
同样要注意$PATH_INFO的用法。就象我在第一课里讲到的，您可以在HTML代
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
码中的任意位置使用PHP。您也会注意到，表格中的每一个元素都对应着数据库中
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
的一个字段。这种对应关系并不是必须的，这么做只是更直观一些，便于您以后
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
理解这些代码。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
还要注意的是，我在Submit按钮中加入了name属性。这样我在程序中可以试
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
探$submit变量是否存在。于是，当网页被再次调用时，我就会知道调用页面时是
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
否已经填写了表格。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
我应该指出，您不一定要把上面的网页内容写到PHP程序中，再返过来调用程
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
序本身。您完全可以把显示表格的网页和处理表格的程序分开放在两个网页、三
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
个网页甚至更多网页中，悉听尊便。放在一个文件中只是可以使内容更加紧凑而
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
已。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
那好，我们现在加入一些代码，来检查用户在表格中输入的内容。我会把用
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$HTTP_POST_VARS把所有查询参数变量都显示出来，这只不过是为了证明PHP确实
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
把所有变量都传给了程序。这种方法是一个很有用的调试手段。如果您要想看全
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
部的变量，可以用$GLOBALS。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
if ($submit) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 处理表格输入
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
while (list($name, $value) = each($HTTP_POST_VARS)) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
echo "$name = $value<br>n";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} else{
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 显示表格
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<form method="post" action="<?php echo $PATH_INFO?>">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
名：<input type="Text" name="first"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
姓：<input type="Text" name="last"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
住址：<input type="Text" name="address"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
职位：<input type="Text" name="position"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<input type="Submit" name="submit" value="输入信息">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</form>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} // end if，if结束
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
程序现在运行正常，那我们现在就可以取到表格输入的内容，并把它们发送
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
给数据库。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
if ($submit) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 处理表格输入
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$db = mysql_connect("localhost", "root");
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
mysql_select_db("mydb",$db);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$sql = "INSERT INTO employees (first,last,address,position)
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
VALUES ('$first','$last','$address','$position')";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query($sql);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
echo "Thank you! Information entered.n";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} else{
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 显示表格内容
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<form method="post" action="<?php echo $PATH_INFO?>">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
名：<input type="Text" name="first"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
姓：<input type="Text" name="last"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
住址：<input type="Text" name="address"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
职位：<input type="Text" name="position"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<input type="Submit" name="submit" value="输入信息">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</form>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} // end if，if结束
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
您现在已经向数据库中插入数据了。不过还有很多完善的工作要做。如果用
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
户没有填写某一栏怎么办？在需要填入数字的地方填了文字怎么办？或者填错了
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
怎么办？
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
别担心。我们一步一步来。>>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
五、修改数据
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
在个教程中，我都把要执行的SQL语句放到一个变量（$sql）中，然后才用m
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
ysql_query()来执行数据库查询。在调试时这是很有用的。如果程序出了什么问
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
题，您随时可以把SQL语句的内容显示出来，检查其中的语法错误。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
我们已经学习了如何把数据插入到数据库中。现在我们来学习如何修改数据
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
库中已有的记录。数据的编辑包括两部分：数据显示和通过表格输入把数据返回
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
给数据库，这两部分我们前面都已经讲到了。然而，数据编辑还是有一点点不同
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
，我们必须先在表格中显示出相关的数据。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
首先，我们回过头再看看第一课的程序代码，在网页中显示员工姓名。但是
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
这次，我们要把数据显示在表格中。程序看起来象下面这样：
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$db = mysql_connect("localhost", "root");
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
mysql_select_db("mydb",$db);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
if ($id) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 查询数据库
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$sql = "SELECT * FROM employees WHERE id=$id";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query($sql);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow = mysql_fetch_array($result);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<form method="post" action="<?php echo $PATH_INFO?>">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<input type=hidden name="id" value="<?php echo $myrow["id"] ?>">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
名：<input type="Text" name="first" value="<?php echo
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["first"] ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
姓：<input type="Text" name="last" value="<?php echo
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["last"] ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
住址：<input type="Text" name="address" value="<?php echo
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["address"] ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
职位：<input type="Text" name="position" value="<?php echo
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["position"] ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<input type="Submit" name="submit" value="输入信息">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</form>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} else {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 显示员工列表
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query("SELECT * FROM employees",$db);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
while ($myrow = mysql_fetch_array($result)) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
printf("<a href="%s?id=%s">%s %s</a><br>n", $PATH_INFO,
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["id"], $myrow["first"], $myrow["last"]);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
我们刚才是把字段内容写入到相应表格元素中的value属性里，这是相应简单
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
的。我们再往前进一步，使程序可以把用户修改过的内容写回数据库去。同样，
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
我们通过Submit按钮来判断是否处理表格输入内容。还要注意，我们用的SQL语句
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
稍稍有些不同。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$db = mysql_connect("localhost", "root");
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
mysql_select_db("mydb",$db);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
if ($id) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
if ($submit) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$sql = "UPDATE employees SET first='$first',last='$last',
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
address='$address',position='$position' WHERE id=$id";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query($sql);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
echo "谢谢！数据更改完成n";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} else {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 查询数据库
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$sql = "SELECT * FROM employees WHERE id=$id";
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query($sql);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow = mysql_fetch_array($result);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<form method="post" action="<?php echo $PATH_INFO?>">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<input type=hidden name="id" value="<?php echo $myrow["id"] ?>">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
名：<input type="Text" name="first" value="<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
echo $myrow["first"] ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
姓：<input type="Text" name="last" value="<?php echo
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["last"] ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
住址：<input type="Text" name="address" value="<?php echo
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["address"] ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
职位：<input type="Text" name="position" value="<?php echo
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["position"] ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<input type="Submit" name="submit" value="输入信息">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</form>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
} else {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
// 显示员工列表
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query("SELECT * FROM employees",$db);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
while ($myrow = mysql_fetch_array($result)) {
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
printf("<a href="%s?id=%s">%s %s</a><br>n", $PATH_INFO,
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$myrow["id"], $myrow["first"], $myrow["last"]);
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
?>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
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</html>
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就是这样。在这个程序中已经包含了我们学过所大多数特性。您也已经看到
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
，我们在一个if()条件判别语句中又加了一个if()语句，来检查多重条件。
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下面，我们要把所有东西全都加在一起，写出一个很好的程序来。>>
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六、完整的程序
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在本课结束前，我们要把所有东西加入到一个程序中，使它具有增加、编辑修改
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
、删除记录的功能。这是前面所有内容的一个延伸，也可以作为极好的复习方法
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。看看下面的程序。
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<html>
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<body>
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<?php
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$db = mysql_connect("localhost", "root");
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mysql_select_db("mydb",$db);
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if ($submit) {
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// 如果没有ID，则我们是在增加记录，否则我们是在修改记录
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if ($id) {
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$sql = "UPDATE employees SET first='$first',last='$last',
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address='$address',position='$position' WHERE id=$id";
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} else {
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$sql = "INSERT INTO employees (first,last,address,position)
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VALUES ('$first','$last','$address','$position')";
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}
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// 向数据库发出SQL命令
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$result = mysql_query($sql);
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echo "记录修改成功！<p>";
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} elseif ($delete) {
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
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// 删除一条记录
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$sql = "DELETE FROM employees WHERE id=$id";
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$result = mysql_query($sql);
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echo "记录删除成功！<p>";
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} else {
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// 如果我们还没有按submit按钮，那么执行下面这部分程序
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
if (!$id) {
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
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// 如果不是修改状态，则显示员工列表
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$result = mysql_query("SELECT * FROM employees",$db);
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while ($myrow = mysql_fetch_array($result)) {
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printf("<a href="%s?id=%s">%s %s</a> n",
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$PATH_INFO, $myrow["id"], $myrow["first"], $myrow["last"]);
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printf("<a href="%s?id=%s&delete=yes">(DELETE)</a><
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br>", $PATH_INFO, $myrow["id"]);
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}
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}
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?>
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<P>
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<a href="<?php echo $PATH_INFO?>">ADD A RECORD</a>
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<P>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<form method="post" action="<?php echo $PATH_INFO?>">
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<?php
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if ($id) {
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// 我们是在编辑修改状态，因些选择一条记录
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$sql = "SELECT * FROM employees WHERE id=$id";
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
$result = mysql_query($sql);
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$myrow = mysql_fetch_array($result);
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$id = $myrow["id"];
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$first = $myrow["first"];
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$last = $myrow["last"];
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$address = $myrow["address"];
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$position = $myrow["position"];
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// 显示id，供用户编辑修改
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?>
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<input type=hidden name="id" value="<?php echo $id ?>">
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<?php
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}
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?>
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
名：<input type="Text" name="first" value="<?php echo $first ?>"><br
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>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
姓：<input type="Text" name="last" value="<?php echo $last ?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
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住址：<input type="Text" name="address" value="<?php echo $address ?
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>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
职位：<input type="Text" name="position" value="<?php echo $position
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?>"><br>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<input type="Submit" name="submit" value="输入信息">
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</form>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
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<?php
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
}
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?>
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chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
</body>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
<`/html>
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
这段程序看起来很复杂，但实际上并不难。程序主要有三个部分。第一个if
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
()语句检查我们是否已经按下了那个“输入信息”的数据提交按钮。如果是，程
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
序再检查$id是否存在。如果不存在，那我们就是在增加记录状态，否则，我们是
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
在修改记录状态。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
接下来我们检查变量$delete是否存在。如果存在，我们是要删除记录。注意
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
，第一个if()语句检查的是用POST方法发送来的变量，而这一次我们检查的是GE
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
T方法中传递过来的变量。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
最后，程序默认的动作是显示员工列表和表格。同样，我们要检查变量$id是
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
否存在。如果存在，我们就根据它的值检索出相应的记录显示出来。否则，我们
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
会显示一个空的表格。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
现在，我们已经把所学的东西全部都放在一个程序里头了。我们用到了whil
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
e()循环，用到了if()语句，并且执行了全部的SQL基本操作 - SELECT、INSERT、
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
UPDATE以及DELETE。另外，我们也知道如何在不同的网页之间通过URL和表格输入
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
来互相传递信息。
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
chinaitpower.com3NqvFhOvShu8nHPUft1PDcwc6
在第三课里，我们要学习如何为网页增加智能化处理能力。
php爱好者站 http://www.ｐｈｐfans.net c/vc/c++/java.
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