MySQL连接查询实例详解
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2024-01-16 16:43:34
本文实例讲述了mysql连接查询。分享给大家供大家参考,具体如下:
创建表suppliers:
create table suppliers
(
s_id...
本文实例讲述了mysql连接查询。分享给大家供大家参考,具体如下:
创建表suppliers:
create table suppliers ( s_id int not null auto_increment, s_name char(50) not null, s_city char(50) null, s_zip char(10) null, s_call char(50) not null, primary key (s_id) ) ; insert into suppliers(s_id, s_name,s_city, s_zip, s_call) values(101,'fastfruit inc.','tianjin','300000','48075'), (102,'lt supplies','chongqing','400000','44333'), (103,'acme','shanghai','200000','90046'), (104,'fnk inc.','zhongshan','528437','11111'), (105,'good set','taiyuang','030000', '22222'), (106,'just eat ours','beijing','010', '45678'), (107,'dk inc.','zhengzhou','450000', '33332');
内连接
select suppliers.s_id, s_name,f_name, f_price from fruits ,suppliers where fruits.s_id = suppliers.s_id;
使用 inner join
语法进行内连接查询
select suppliers.s_id, s_name,f_name, f_price from fruits inner join suppliers on fruits.s_id = suppliers.s_id;
创建表orders:
create table orders ( o_num int not null auto_increment, o_date datetime not null, c_id int not null, primary key (o_num) ) ; insert into orders(o_num, o_date, c_id) values(30001, '2008-09-01', 10001), (30002, '2008-09-12', 10003), (30003, '2008-09-30', 10004), (30004, '2008-10-03', 10005), (30005, '2008-10-08', 10001);
左连接
select customers.c_id, orders.o_num from customers left outer join orders on customers.c_id = orders.c_id;
右连接
select customers.c_id, orders.o_num from customers right outer join orders on customers.c_id = orders.c_id;
复合条件连接查询
select customers.c_id, orders.o_num from customers inner join orders on customers.c_id = orders.c_id and customers.c_id = 10001; select suppliers.s_id, s_name,f_name, f_price from fruits inner join suppliers on fruits.s_id = suppliers.s_id order by fruits.s_id;
【例.46】在fruits表和suppliers表之间使用内连接查询,查询之前,查看两个表的结构
select suppliers.s_id, s_name,f_name, f_price from fruits ,suppliers where fruits.s_id = suppliers.s_id;
【例.47】在fruits表和suppliers表之间使用inner join
语法进行内连接查询
select suppliers.s_id, s_name,f_name, f_price from fruits inner join suppliers on fruits.s_id = suppliers.s_id;
【例.48】查询供应f_id='a1'的水果供应商提供的其他水果种类
select f1.f_id, f1.f_name from fruits as f1, fruits as f2 where f1.s_id = f2.s_id and f2.f_id = 'a1';
【例.49】在customers表和orders表中,查询所有客户,包括没有订单的客户,sql语法如下
select customers.c_id, orders.o_num from customers left outer join orders on customers.c_id = orders.c_id;
【例.50】在customers表和orders表中,查询所有订单,包括没有客户的订单
select customers.c_id, orders.o_num from customers right outer join orders on customers.c_id = orders.c_id;
【例.51】在customers表和orders表中,使用inner join
语法查询customers表中id为10001、的客户的订单信息
select customers.c_id, orders.o_num from customers inner join orders on customers.c_id = orders.c_id and customers.c_id = 10001;
【例.52】在fruits表和suppliers表之间使用inner join
语法进行内连接查询,并对查询结果排序
select suppliers.s_id, s_name,f_name, f_price from fruits inner join suppliers on fruits.s_id = suppliers.s_id order by fruits.s_id;
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希望本文所述对大家mysql数据库计有所帮助。