MySQL子查询操作实例详解
网络 2018-06-29 1361
本文实例总结了MySQL子查询操作。分享给大家供大家参考，具体如下：
定义两个表tb1和tb2
1 2 | CREATE table tbl1 ( num1 INT NOT NULL); CREATE table tbl2 ( num2 INT NOT NULL); |
向两个表中插入数据：
1 2 | INSERT INTO tbl1 values(1), (5), (13), (27); INSERT INTO tbl2 values(6), (14), (11), (20); |
any some关键字的子查询
1 2 3 | SELECT num1 FROM tbl1 WHERE num1 > ANY (SELECT num2 FROM tbl2); |
all关键字的子查询
1 2 3 | SELECT num1 FROM tbl1 WHERE num1 > ALL (SELECT num2 FROM tbl2); |
exists关键字的子查询
1 2 3 4 5 6 7 8 9 10 11 | SELECT * from fruits WHERE EXISTS (SELECT s_name FROM suppliers WHERE s_id = 107); SELECT * from fruits WHERE f_price>10.20 AND EXISTS (SELECT s_name FROM suppliers WHERE s_id = 107); SELECT * from fruits WHERE NOT EXISTS (SELECT s_name FROM suppliers WHERE s_id = 107); |
带in关键字的子查询
1 2 3 4 5 6 7 | SELECT c_id FROM orders WHERE o_num IN (SELECT o_num FROM orderitems WHERE f_id = 'c0'); SELECT c_id FROM orders WHERE o_num NOT IN (SELECT o_num FROM orderitems WHERE f_id = 'c0'); |
带比较运算符的子查询
1 2 3 | SELECT s_id, f_name FROM fruits WHERE s_id = (SELECT s1.s_id from suppliers AS s1 WHERE s1.s_city = 'Tianjin'); |
<>所有非
1 2 3 | SELECT s_id, f_name FROM fruits WHERE s_id <> (SELECT s1.s_id from suppliers AS s1 WHERE s1.s_city = 'Tianjin'); |
定义两个表tb1和tb2
1 2 | CREATE table tbl1 ( num1 INT NOT NULL); CREATE table tbl2 ( num2 INT NOT NULL); |
向两个表中插入数据
1 2 | INSERT INTO tbl1 values(1), (5), (13), (27); INSERT INTO tbl2 values(6), (14), (11), (20); |
【例.53】返回tbl2表的所有 num2 列，然后将 tbl1 中的 num1 的值与之进行比较，只要大于 num2的任何值为符合查询条件的结果
1 2 3 | SELECT num1 FROM tbl1 WHERE num1 > ANY (SELECT num2 FROM tbl2); |
【例.54】返回tbl1表的中比tbl2表num2 列所有值都大的值
1 2 3 | SELECT num1 FROM tbl1 WHERE num1 > ALL (SELECT num2 FROM tbl2); |
【例.55】查询表suppliers表中是否存在s_id=107的供应商，如果存在则查询fruits表中的记录
1 2 3 | SELECT * from fruits WHERE EXISTS (SELECT s_name FROM suppliers WHERE s_id = 107); |
【例.56】查询表suppliers表中是否存在s_id=107的供应商，如果存在则查询fruits表中的f_price大于10.20的记录
1 2 3 | SELECT * from fruits WHERE f_price>10.20 AND EXISTS (SELECT s_name FROM suppliers WHERE s_id = 107); |
【例.57】查询表suppliers表中是否存在s_id=107的供应商，如果不存在则查询fruits表中的记录
1 2 3 | SELECT * from fruits WHERE NOT EXISTS (SELECT s_name FROM suppliers WHERE s_id = 107); |
【例.58】在orderitems表中查询订购f_id为c0的订单号，并根据订单号查询具有订单号的客户c_id
1 2 | SELECT c_id FROM orders WHERE o_num IN (SELECT o_num FROM orderitems WHERE f_id = 'c0'); |
【例.59】与前一个例子语句类似，但是在SELECT语句中使用NOT IN操作符
1 2 | SELECT c_id FROM orders WHERE o_num NOT IN (SELECT o_num FROM orderitems WHERE f_id = 'c0'); |
【例.60】在suppliers表中查询s_city等于Tianjin的供应商s_id，然后在fruits表中查询所有该供应商提供的水果的种类
1 2 3 | SELECT s_id, f_name FROM fruits WHERE s_id = (SELECT s1.s_id from suppliers AS s1 WHERE s1.s_city = 'Tianjin'); |
【例.61】在suppliers表中查询s_city等于Tianjin的供应商s_id，然后在fruits表中查询所有非该供应商提供的水果的种类，SQL语句如下：
1 2 3 | SELECT s_id, f_name FROM fruits WHERE s_id <> (SELECT s1.s_id from suppliers AS s1 WHERE s1.s_city = 'Tianjin'); |
