游标

时间：2010-10-14 来源：ljh0242

15-1:使用标量变量接收游标数据
DECLARE
CURSOR emp_cursor IS
SELECT ename,job,sal FROM emp WHERE deptno=&dno;
v_ename emp.ename%TYPE;
v_sal emp.sal%TYPE;
v_job emp.job%TYPE;
BEGIN
OPEN emp_cursor;
LOOP
FETCH emp_cursor INTO v_ename,v_job,v_sal;
EXIT WHEN emp_cursor%NOTFOUND;
dbms_output.put_line('姓名：'||v_ename||'，岗位：'||v_job||'，工资：'||v_sal);
END LOOP;
CLOSE emp_cursor;
END;
/
15-2:使用pl/sql纪录变量接收游标数据
DECLARE
CURSOR emp_cursor IS
SELECT ename,sal FROM emp ORDER BY sal DESC;
emp_record emp_cursor%ROWTYPE;
BEGIN
OPEN emp_cursor;
LOOP
FETCH emp_cursor INTO emp_record;
EXIT WHEN emp_cursor%NOTFOUND OR emp_cursor%ROWCOUNT>&n;
dbms_output.put_line('姓名：'||emp_record.ename||
'，工资：'||emp_record.sal);
END LOOP;
CLOSE emp_cursor;
END;
/
15-3:使用pl/sql集合变量接收游标数据
DECLARE
CURSOR emp_cursor IS SELECT ename,sal FROM emp
WHERE lower(job)=lower('&job');
TYPE emp_table_type IS TABLE OF emp_cursor%ROWTYPE
INDEX BY BINARY_INTEGER;
emp_table emp_table_type;
i INT;
BEGIN
OPEN emp_cursor;
LOOP
i:=emp_cursor%ROWCOUNT+1;
FETCH emp_cursor INTO emp_table(i);
EXIT WHEN emp_cursor%NOTFOUND;
dbms_output.put_line('姓名：'||emp_table(i).ename||
'，工资：'||emp_table(i).sal);
END LOOP;
CLOSE emp_cursor;
END;
/
15-4:在游标for循环中引用已定义游标
DECLARE
CURSOR emp_cursor IS SELECT ename,hiredate FROM emp
ORDER BY hiredate DESC;
BEGIN
FOR emp_record IN emp_cursor LOOP
dbms_output.put_line('姓名：'||emp_record.ename
||',工作日期：'||emp_record.hiredate);
EXIT WHEN emp_cursor%ROWCOUNT=&n;
END LOOP;
END;
/
15-5:在游标for循环中直接引用子查询
BEGIN
FOR emp_record IN (SELECT ename,hiredate,rownum FROM emp
ORDER BY hiredate) LOOP
dbms_output.put_line('姓名：'||emp_record.ename
||',工作日期：'||emp_record.hiredate);
EXIT WHEN emp_record.rownum=&n;
END LOOP;
END;
/
15-6:参数游标
DECLARE
CURSOR emp_cursor(dno NUMBER) IS
SELECT ename,job FROM emp WHERE deptno=dno;
BEGIN
FOR emp_record IN emp_cursor(&dno) LOOP
dbms_output.put_line('姓名：'||emp_record.ename
||',岗位：'||emp_record.job);
END LOOP;
END;
/
15-7:更新游标行
DECLARE
CURSOR emp_cursor IS
SELECT ename,sal,deptno FROM emp FOR UPDATE;
dno INT:=&no;
BEGIN
FOR emp_record IN emp_cursor LOOP
IF emp_record.deptno=dno THEN
dbms_output.put_line('姓名:'||emp_record.ename
||',原工资:'||emp_record.sal);
UPDATE emp SET sal=sal*1.1 WHERE CURRENT OF emp_cursor;
END IF;
END LOOP;
END;
/
15-8:删除游标行
DECLARE
CURSOR emp_cursor IS
SELECT ename FROM emp FOR UPDATE;
name VARCHAR2(10):=lower('&name');
BEGIN
FOR emp_record IN emp_cursor LOOP
IF lower(emp_record.ename)=name THEN
DELETE FROM emp WHERE CURRENT OF emp_cursor;
ELSE
dbms_output.put_line('姓名:'||emp_record.ename);
END IF;
END LOOP;
END;
/
15-9:使用of子句在特定表上加行共享锁．
DECLARE
CURSOR emp_cursor IS
SELECT a.dname,b.ename FROM dept a JOIN emp b
ON a.deptno=b.deptno
FOR UPDATE OF b.deptno;
name VARCHAR2(10):=LOWER('&name');
BEGIN
FOR emp_record IN emp_cursor LOOP
IF LOWER(emp_record.dname)=name THEN
dbms_output.put_line('姓名:'||emp_record.ename);
DELETE FROM emp WHERE CURRENT OF emp_cursor;
END IF;
END LOOP;
END;
/
15-10:使用无返回类型的游标变量
DECLARE
TYPE ref_cursor_type IS REF CURSOR;
ref_cursor ref_cursor_type;
v1 NUMBER(6);
v2 VARCHAR2(10);
BEGIN
OPEN ref_cursor FOR
SELECT &col1 col1,&col2 col2 FROM &table WHERE &cond;
LOOP
FETCH ref_cursor INTO v1,v2;
EXIT WHEN ref_cursor%NOTFOUND;
dbms_output.put_line('col1='||v1||',col2='||v2);
END LOOP;
CLOSE ref_cursor;
END;
/
15-11:使用有返回类型的游标变量
DECLARE
TYPE emp_cursor_type IS REF CURSOR RETURN emp%ROWTYPE;
emp_cursor emp_cursor_type;
emp_record emp%ROWTYPE;
BEGIN
OPEN emp_cursor FOR SELECT * FROM emp
WHERE deptno=&dno;
LOOP
FETCH emp_cursor INTO emp_record;
EXIT WHEN emp_cursor%NOTFOUND;
dbms_output.put_line('姓名:'||emp_record.ename||
',工资:'||emp_record.sal);
END LOOP;
CLOSE emp_cursor;
END;
/
15-12:使用fetch...bulk collect提取所有数据
DECLARE
CURSOR emp_cursor IS
SELECT * FROM emp WHERE LOWER(job)=LOWER('&job');
TYPE emp_table_type IS TABLE OF emp%ROWTYPE;
emp_table emp_table_type;
BEGIN
OPEN emp_cursor;
FETCH emp_cursor BULK COLLECT INTO emp_table;
CLOSE emp_cursor;
FOR i IN 1.. emp_table.COUNT LOOP
dbms_output.put_line('姓名:'||emp_table(i).ename
||',工资:'||emp_table(i).sal);
END LOOP;
END;
/
15-13:使用limit子句限制提取行数
DECLARE
CURSOR emp_cursor IS SELECT * FROM emp;
TYPE emp_array_type IS VARRAY(5) OF emp%ROWTYPE;
emp_array emp_array_type;
BEGIN
OPEN emp_cursor;
LOOP
FETCH emp_cursor BULK COLLECT INTO emp_array LIMIT &rows;
FOR i IN 1..emp_array.COUNT LOOP
dbms_output.put_line('姓名:'||emp_array(i).ename
||',工资:'||emp_array(i).sal);
END LOOP;
EXIT WHEN emp_cursor%NOTFOUND;
END LOOP;
CLOSE emp_cursor;
END;
/
15-14:使用cursor表达式
DECLARE
CURSOR dept_cursor(no NUMBER) IS
SELECT a.dname,CURSOR(SELECT * FROM emp
WHERE deptno=a.deptno)
FROM dept a WHERE a.deptno=no;
TYPE ref_cursor_type IS REF CURSOR;
emp_cursor ref_cursor_type;
emp_record emp%ROWTYPE;
v_dname dept.dname%TYPE;
BEGIN
OPEN dept_cursor(&dno);
LOOP
FETCH dept_cursor INTO v_dname,emp_cursor;
EXIT WHEN dept_cursor%NOTFOUND;
dbms_output.put_line('部门名:'||v_dname);
LOOP
FETCH emp_cursor INTO emp_record;
EXIT WHEN emp_cursor%NOTFOUND;
dbms_output.put_line('----雇员名:'||emp_record.ename
||',岗位:'||emp_record.job);
END LOOP;
END LOOP;
CLOSE dept_cursor;
END;
/