MySQL子查询操作实例详解

数据库  /  管理员 发布于 6年前   738

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 num1FROM tbl1WHERE num1 > ANY (SELECT num2 FROM tbl2);

all关键字的子查询

SELECT num1FROM tbl1WHERE num1 > ALL (SELECT num2 FROM tbl2);

exists关键字的子查询

SELECT * from fruitsWHERE EXISTS(SELECT s_name FROM suppliers WHERE s_id = 107);SELECT * from fruitsWHERE f_price>10.20 AND EXISTS(SELECT s_name FROM suppliers WHERE s_id = 107);SELECT * from fruitsWHERE NOT EXISTS(SELECT s_name FROM suppliers WHERE s_id = 107);

带in关键字的子查询

SELECT c_idFROM ordersWHERE o_num IN (SELECT o_num FROM orderitems WHERE f_id = 'c0');SELECT c_idFROM ordersWHERE 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 fruitsWHERE s_id =(SELECT s1.s_id from suppliers AS s1 WHERE s1.s_city = 'Tianjin');

<>所有非

SELECT s_id, f_name FROM fruitsWHERE 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 num1FROM tbl1WHERE 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 num1FROM tbl1WHERE 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 fruitsWHERE 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 fruitsWHERE 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 fruitsWHERE 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 fruitsWHERE 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 fruitsWHERE s_id <>(SELECT s1.s_id from suppliers AS s1 WHERE s1.s_city = 'Tianjin');

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希望本文所述对大家MySQL数据库计有所帮助。