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：

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》

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