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+------+----------+---------+ | id | name | dept_id | +------+----------+---------+ | 2 | Dennis-2 | DEv | | 1 | Dennis-1 | R&D | | 3 | Dennis-3 | R&D | | 4 | Dennis-4 | Test | | 5 | Dennis-5 | Test | +------+----------+---------+ 5 rows in set (0.00 sec) # 我们再把 table 的位置交换一下,再用 right join 试试 select a.id,a.name,b.dept_id from emp_dept b right join emp a on (a.id=b.emp_id); mysql> select a.id,a.name,b.dept_id -> from emp_dept b right join emp a on (a.id=b.emp_id); +----+-----------+---------+ | id | name | dept_id | +----+-----------+---------+ | 1 | Dennis-1 | R&D | | 2 | Dennis-2 | DEv | | 3 | Dennis-3 | R&D | | 4 | Dennis-4 | Test | | 5 | Dennis-5 | Test | | 6 | Dennis-6 | NULL | | 7 | Dennis-7 | NULL | | 8 | Dennis-8 | NULL | | 9 | Dennis-9 | NULL | | 10 | Dennis-10 | NULL | +----+-----------+---------+
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正在阅读：数据库学习:MySQL Join详解数据库学习:MySQL Join详解
2004-04-01 13:26
出处：CSDN
责任编辑：linjixiong
键盘也能翻页，试试“← →”键
