表不存在时创建表

mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| enum_test      |
| index_test     |
+----------------+
2 rows in set (0.00 sec)

mysql> create table if not exists a(id INT not null, name VARCHAR(15) not null, age INT UNSIGNED not null);
Query OK, 0 rows affected (0.01 sec)

mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| a              |
| enum_test      |
| index_test     |
+----------------+
3 rows in set (0.00 sec)

mysql> create table if not exists a(id INT not null, name VARCHAR(15) not null, age INT UNSIGNED not null);
Query OK, 0 rows affected, 1 warning (0.01 sec)

mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| a              |
| enum_test      |
| index_test     |
+----------------+
3 rows in set (0.00 sec)

跑程序的时候特别是c程序的时候 建议创建表 加上if not exist....