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ALTER TABLE items 
ADD CONSTRAINT member_1  
FOREIGN KEY(Member_ID)
REFERENCES users(UserID)
ON UPDATE CASCADE
ON DELETE CASCADE;

MySQL said:

1452 - Cannot add or update a child row: a foreign key constraint fails (`shop`.`#sql-1650_234`, CONSTRAINT `member_1` FOREIGN KEY (`Member_ID`) REFERENCES `users` (`UserID`) ON DELETE CASCADE ON UPDATE CASCADE)

Midas
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ace francis eli
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1 Answers1

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You must to fix incorrect values before create new constraint:

Update items SET member_ID = null
where member_ID not in (select userID from users)
vp_arth
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