从两个表中获取值，其中之一是多对多

Question

我只想获取那些没有附加mtm.can_id = 2的v.v_name。怎么做？

P.S. v.id = mtm.vac_id

空缺表：

 
+----+--------------------------+ 
| Id |   v_name   | 
+----+--------------------------+ 
| 1 | Registered Nurse   | 
| 2 | Pharmacist    | 
| 7 | Dentist     | 
| 8 | Computer Systems Analyst | 
| 9 | Physician    | 
+----+--------------------------+ 

逐日盯表：

 
+----+--------+--------+ 
| Id | can_id | vac_id | 
+----+--------+--------+ 
| 1 |  1 |  1 | 
| 2 |  1 |  2 | 
| 3 |  2 |  2 | 
| 4 |  37 |  2 | 
| 5 |  37 |  1 | 
+----+--------+--------+ 

预期结果：

 
+---+--------------------------+ 
| 7 | Dentis 
| 1 | Registered Nurse   
| 8 | Computer Systems Analyst 
| 9 | Physician     
+---+--------------------------+ 

Answer 1

这应该为你工作

select * from vacancy where id not in (select distinct vac_id from mtm where can_id = 2) 

Answer 2

，如果你想获得的所有结果是不

mtm.can_id = 2然后检查但未测试

select * from v_table where id not in (select distinct vac_id from mtm_table where mtm.can_id = 2)