What is the expression that will always be true while using SQL WHERE IN comparison query

Question

SELECT *  
FROM TABLE_X  
WHERE 'Value' IN (SELECT * FROM TABLE_Y)

What expression can I use instead of 'Value' so that the WHERE clause where always return true?

I am trying to do something like:

WHERE (SELECT field FROM TABLE_Y) LIKE '%Value%'

If you need to return true always then use 1 = 1 or no where clause at all. But comparing `value` with `Table_Y`, I think you should explain your requirement more clearly. — Esty, Oct 19 '16 at 11:41

score 1 · Accepted Answer · edited Oct 19 '16 at 13:20

1

Found the solution, use EXISTS instead of WHERE IN:

SELECT *  
FROM TABLE_X   
WHERE EXISTS (SELECT field FROM TABLE_Y WHERE field LIKE '%Value%')

edited Oct 19 '16 at 13:20

jarlh

answered Oct 19 '16 at 11:46

Rami Zebian

score 0 · Answer 2 · answered Oct 19 '16 at 11:43

I don't know if I understood it well, it's silly to do the following, but returns all the records in TABLE_X:

SELECT *
FROM TABLE_X 
WHERE 1 IN (SELECT field FROM TABLE_Y)

NOTE: ...IN (SELECT * ...) crashes because you should choose just one column, that's why I wrote field instead of *

Battle Mage · Answer 3 · 2016-10-19T11:51:39.893

0

You cannot compare your 'Value' with *, you need a specified field from TABLE_Y, for example:

SELECT * 
FROM TABLE_X
WHERE (SELECT Field FROM TABLE_Y WHERE Field LIKE '%Value%' LIMIT 1) IS NOT NULL

edited Oct 19 '16 at 11:51

answered Oct 19 '16 at 11:46

Battle Mage

3 Answers3