-- Check existing constraints on _userfollows table
SHOW INDEX FROM _userfollows;

-- Drop the duplicate constraint if it exists
ALTER TABLE _userfollows DROP INDEX IF EXISTS `_userfollows_AB_unique`;

-- Check if the table exists and its structure
SHOW CREATE TABLE _userfollows;

-- Recreate the correct constraint if needed
ALTER TABLE _userfollows ADD CONSTRAINT `_userfollows_AB_unique` UNIQUE (`A`, `B`);