Question : MySQL: How to update records with subselect in where clause

I have migrated my application from MSSQL to MySQL and this is the last query that I can't figure out. I have a join table called ContactOwner which allows many AppUsers (AppUserOwnerId) to be associated with many Contacts (ContactId). In simple terms, it allows the application to know what user(s) own a particular Contact. I would like to delete all the rows for an AppUser where he is a "co-owner" with another specific user. The Query below did the trick in MSSQL, but MySQL objects to the sub-select near the "in" clause.

-- Deletes all rows where appUserId1 co-owns a contact with AppUserId2 (for appUserId1 only - appUserId2's rown still remain)
Delete From ContactOwner
where AppUserIdOwner = 1 and
ContactId in (select contactId from ContactOwner where AppUserIdOwner = 2)

ContactOwner Table
Col 1: ContactId
Col 2: AppUserIdOwner

Is there another way to skin this cat? I would prefer the solution to still be a single SQL statement.

Answer : MySQL: How to update records with subselect in where clause

Use a JOIN.

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DELETE co
FROM ContactOwner co
INNER JOIN ContactOwner lkup
   ON lkup.ContactID = co.ContactID
WHERE co.AppUserIdOwner = 1
AND lkup.AppUserIdOwner = 2
;

Question : MySQL: How to update records with subselect in where clause

Answer : MySQL: How to update records with subselect in where clause

Use a JOIN. 1: 2: 3: 4: 5: 6: 7: DELETE co FROM ContactOwner co INNER JOIN ContactOwner lkup ON lkup.ContactID = co.ContactID WHERE co.AppUserIdOwner = 1 AND lkup.AppUserIdOwner = 2 ;

Use a JOIN.

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DELETE co FROM ContactOwner co INNER JOIN ContactOwner lkup ON lkup.ContactID = co.ContactID WHERE co.AppUserIdOwner = 1 AND lkup.AppUserIdOwner = 2 ;