SQL : select rows with value in some column and the value does is not contained in another table

Question

There are two tables

Students :

ID | Name | Age
---+------+-----
1  | Alex | 19
2  | Matt | 23
3  | Ali  | 19

Actions :

ACTIONID | Description
---------+---------------------------
1        | Alex hasn't paid yet

I want to select Student ID with age 19. But don't want to select student whose name is contained in any row of description column from the Actions table.

So result should be the following

ID: 3

How to do that? Could anybody help me?

Answer 1

Try this:

SELECT student.ID 
FROM Students student
WHERE 0 = (SELECT COUNT(*) 
           FROM Actions action 
           WHERE action.Description LIKE CONCAT('%', student.Name, '%')
AND student.Age = 19;

Answer 2

如果我理解你的问题。

select ID from Students where Age = 19