从一个表中选择所有字段，其中另一个ID为ID的表中的字段等于一个字符串

Question

I have 2 tables:

Ads : Fields ID , A , B and C :

+----+---+-------+------+
| ID | A | B     | C    |
+----+---+-------+------+
|  1 | x | y     | z    |
|  2 | c | v     | b    |
|  3 | n | n     | m    |
+----+---+-------+------+

Requests : Fields ID , AdID , and Status :

+----+------+----------+
| ID | AdID |  Status  |
+----+------+----------+
|  3 |    1 | pending  |
|  4 |    2 | approved |
|  5 |    3 | pending  |
+----+------+----------+

ID (from Ads ) = AdID (from Requests ).

Now, I want to get all records from Ads where AdID 's (from Requests ) Status equals pending . AdId here would be the value ID from Ads .

So, with the above tables, the result I'd get would be ID 1 and 3 from Ads:

+----+---+---+---+
| ID | A | B | C |
+----+---+---+---+
|  1 | x | y | z |
|  3 | n | n | m |
+----+---+---+---+

This is the closest I've got so far, but this obviously doesn't work because it can only select one row - whereas I need to select many:

SELECT * FROM Ads WHERE ID = (SELECT AdID FROM Requests WHERE Status = 'pending')

This might not make sense - please ask if I haven't explained it well - I'll help as much as possible :)

Answer 1

Use IN in place of = :

SELECT * 
FROM Ads 
WHERE ID IN (SELECT AdID FROM Requests WHERE Status = 'pending')

Answer 2

尝试这个：

SELECT * FROM Ads A LEFT JOIN Requests R ON A.ID=R.AdID WHERE R.AdID='pending';