复合条件连接查询是在连接查询的过程中,通过添加过滤条件,限制查询的结果,使查询的结果更加准确
mysql> SELECT customers.c_id, orders.o_num FROM customers INNER JOIN orders ON customers.c_id = orders.c_id AND customers.c_id = 10001; +-------+-------+ | c_id | o_num | # 在连接查询时指定查询客户ID为10001的订单信息,添加了过滤条件后返回的结果将会变少 +-------+-------+ | 10001 | 30001 | | 10001 | 30005 | +-------+-------+
时间: 2024-07-28 20:56:20