MySQL连接查询实例详解

时间：2021-12-08 02:50:17

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;

 

希望本文所述对大家MySQL数据库计有所帮助。

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