sql-从一个表中选择另一个表中不存在的记录

Question

I am trying to select all the records from the table "users" that do not exists in the table "clubs". However, the sentence is still showing some records that exist in the table "clubs".

Table: Users

ID, Name, Registration_Date
***************************
3, Mark, 5/1/2017
7, Paul, 5/2/2017
8, John, 5/3/2017

Table: Clubs

************
User_ID, Club_Name
  3, Chicago
  3, Texas
  7, Miami
  7, San Antonio

This is the SQL sentence:

---

SELECT 
    [Users].[ID], 
    [Users].[Name]
FROM 
    [Users]
LEFT JOIN 
    [Clubs]
ON 
    [Users].[ID] = [Clubs].[User_ID]  
WHERE
    [Clubs].[User_ID] IS NULL AND
    [Users].[Status] = 'Active' AND
    [Users].[Gender] = 'Female'
GROUP BY 
    [Users].[ID],
    [Users].[Name]
ORDER BY 
    [Users].[ID] DESC

This is the result that I am getting

---

8, John
3, Mark

For some reason, the user with ID 3 is still showing, which exists in the "clubs" table.

Any help is greatly appreciated.

Answer 1

It reads like English: Select from User where User.Id is not in Clubs. Here is the query:

SELECT 
    [Users].[ID], 
    [Users].[Name]
FROM 
    [Users]
WHERE
    [Users].[Status] = 'Active' AND
    [Users].[Gender] = 'Female' AND 
    [Users].[ID] not in (select UserID from Clubs)
ORDER BY 
    [Users].[ID] DESC

More info about the IN operator .

Answer 2

This was the resolution to the problem provided by James:

Check if there is an extra space (or something like that) in either table for the id field for the "3" records, which may cause it not to match correctly. I've recreated that DB locally and the query worked for me. –

The problem was a space in the column Status.

I added this comment as the right answer was provided as a comment, and did not find any other option to accept the comment as the right answer.

Answer 3

Try this

SELECT 
    [Users].[ID], 
    [Users].[Name]
FROM 
    [Users]
WHERE
    [Users].[ID] NOT IN (SELECT [Clubs].[User_ID] FROM [Clubs]) AND
    [Users].[Status] = 'Active' AND
    [Users].[Gender] = 'Female'
GROUP BY 
    [Users].[ID],
    [Users].[Name]
ORDER BY 
    [Users].[ID] DESC

Answer 4

Updated Query

SELECT 
[Users].[ID], 
[Users].[Name]
FROM 
[Users]
WHERE
[Users].[ID] IN 
(SELECT [Users].[ID] except (SELECT UserId from Clubs group by Clubs.UserId)) 
AND
[Users].[Gender] = 'Female' AND
[Users].[Status] = 'Active' // other filters as necessary
ORDER BY 
[Users].[ID] DESC

May need to do an execution plan, may not be perfomant, but gives you the necessary result

Answer 5

  SELECT [Users].[ID], [Users].[Name] 
  FROM [Users]  
  WHERE not exists(Select 1 from [Clubs] where [Clubs].[User_ID]=[Users].[ID]) 
  AND [Users].[Status] = 'Active' 
  AND [Users].[Gender] = 'Female' 
  GROUP BY [Users].[ID], [Users].[Name] 
  ORDER BY [Users].[ID] DESC

User ID not exists in the Club table and do exists in the Users table will be fetched.

Answer 6

I think the problem is the left join.

Change this: FROM [Users] LEFT JOIN [Clubs]

For this: FROM [Users] RIGHT JOIN [Clubs]