sql中join的修饰字段(left,right,inner)的区别
2017-09-07 11:11
405 查看
left join(左联接) 返回包括左表中的所有记录和右表中联结字段相等的记录
SELECT d.*,e.SAL FROM dept d LEFT JOIN emp e ON SAL>1500
right join(右联接) 返回包括右表中的所有记录和左表中联结字段相等的记录
SELECT d.*,e.SAL FROM dept d RIGHT JOIN emp e ON SAL>1500
inner join(等值连接) 只返回两个表中联结字段相等的行
SELECT d.*,e.SAL FROM dept d INNER JOIN emp e ON SAL>1500
SELECT d.*,e.SAL FROM dept d LEFT JOIN emp e ON SAL>1500
right join(右联接) 返回包括右表中的所有记录和左表中联结字段相等的记录
SELECT d.*,e.SAL FROM dept d RIGHT JOIN emp e ON SAL>1500
inner join(等值连接) 只返回两个表中联结字段相等的行
SELECT d.*,e.SAL FROM dept d INNER JOIN emp e ON SAL>1500
相关文章推荐
- SQL中各种Join语句(left、right、full、inner)的区别
- sql中left、inner、right join on和where的区别
- sql语法中的inner join on, left join on和 right join on的区别和详细使用方法(转载)
- sql之 left join /right join/ inner join/之间的区别
- 2006-5-20 SQL 外链接操作小结 inner join & left join & right join
- sql语法:inner join on, left join on, right join on具体用法
- SQL--inner join on, left join on, right join on
- SQL语法:inner join on, left join on, right join on详细使用方法
- sql内连接,等值连接,左连接和右连接的使用技巧(inner join and left join and right join)
- SQL中的left outer join,inner join,right outer join用法及区别
- sql语法:inner join on, left join on, right join on详细使用方法
- sql语法:inner join on, left join on, right join on详细使用方法
- SQL语法: inner join on, left join on,right join on详细使用方法
- sql中 inner/left/right join on的用法
- SQL 外链接操作小结 inner join left join right join
- left (outer) join , right (outer) join, full (outer) join, (inner) join, cross join 区别
- sql语法:inner join on, left join on, right join on详细使用方法
- sql left join right join 的区别
- sql语法:inner join on, left join on, right join on具体用法
- sql语法:inner join on, left join on, right join on详细使用方法