四川盐亭网站制作公司

MySQL子查询操作实例详解

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：

公司主营业务：网站设计、成都网站建设、移动网站开发等业务。帮助企业客户真正实现互联网宣传，提高企业的竞争能力。成都创新互联公司是一支青春激扬、勤奋敬业、活力青春激扬、勤奋敬业、活力澎湃、和谐高效的团队。公司秉承以“开放、自由、严谨、自律”为核心的企业文化，感谢他们对我们的高要求，感谢他们从不同领域给我们带来的挑战，让我们激情的团队有机会用头脑与智慧不断的给客户带来惊喜。成都创新互联公司推出积石山保安族东乡族免费做网站回馈大家。

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。


新闻标题：MySQL子查询操作实例详解
文章源于：http://scyanting.com/article/poieeg.html

其他资讯