MySQL子查询操作实例详解
发布时间：2022-03-14 11:53:42 所属栏目：MySql教程 来源：互联网
导读：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 CREATE table tbl1 ( num1 INT NOT NULL); CREATE table tbl2 ( num2 INT NOT NULL); 向两个表中插入数据： INSERT INTO tbl1 values(1), (5), (13), (27); INSERT I
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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 CREATE table tbl1 ( num1 INT NOT NULL); CREATE table tbl2 ( num2 INT NOT NULL); 向两个表中插入数据： 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 SELECT num1 FROM tbl1 WHERE num1 > ANY (SELECT num2 FROM tbl2); all关键字的子查询 SELECT num1 FROM tbl1 WHERE num1 > ALL (SELECT num2 FROM tbl2); exists关键字的子查询 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 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 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 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 CREATE table tbl1 ( num1 INT NOT NULL); CREATE table tbl2 ( num2 INT NOT NULL); 向两个表中插入数据 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 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 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 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 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 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 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 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 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： SELECT s_id, f_name FROM fruits WHERE s_id <> (SELECT s1.s_id from suppliers AS s1 WHERE s1.s_city = 'Tianjin'); 更多关于MySQL相关内容感兴趣的读者可查看本站专题：《MySQL常用函数大汇总》、《MySQL日志操作技巧大全》、《MySQL事务操作技巧汇总》、《MySQL存储过程技巧大全》及《MySQL数据库锁相关技巧汇总》 希望本文所述对大家MySQL数据库计有所帮助。 （编辑：温州站长网） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |
