Question

Here is the simple sql query that will return all tables that have the following column name, ‘userid’ or ‘user_id’.

SELECT  t.name 
FROM sys.tables t
INNER JOIN sys.columns c ON t.object_id = c.object_id
WHERE c.name LIKE 'userid' OR c.name LIKE 'user_id'
ORDER BY name

However, what I would like to do here is to get all the tables that don’t contain ‘userid’ column and ‘user_id’ column. How should I query this?

P.S. Using NOT LIKE will still bring back the table that contains ‘userid’ or ‘user_id’ column, if the table has some other different columns.

Thanks very much.

Answer 1

You need “tables where no column userid/user_id exists”

SELECT
    t.name 
FROM 
    sys.tables t
WHERE
    NOT EXISTS (SELECT *
          FROM sys.columns c
          WHERE t.object_id = c.object_id AND c.name IN ('userid', 'user_id'))
ORDER BY
    t.name

Edit:

You can also use your original query in an EXCEPT clause

SELECT t.name FROM sys.tables t
EXCEPT
SELECT t.name 
FROM sys.tables t
INNER JOIN sys.columns c ON t.object_id = c.object_id
WHERE c.name IN  ('userid', 'user_id')
ORDER BY t.name

These two queries should give identical plans and performance