ALTER TABLE market ADD FOREIGN KEY (buyer_id, seller_id) REFERENCES
accounts (id) ON DELETE SET NULL ON UPDATE CASCADE;
[b]Fehlermeldung:[/b] ERROR 1005 (HY000): Can't create table './d00e434e/#sql-13d9_4309ea.frm' (errno: 150)

ALTER TABLE market_transactions ADD FOREIGN KEY (seller_id) REFERENCES
 accounts (id) ON DELETE SET NULL ON UPDATE CASCADE;
[b]Fehlermeldung:[/b]ERROR 1452 (23000):
 Cannot add or update a child row: a foreign key constraint 
fails (`d00e434e/#sql-13d9_4309ea`, CONSTRAINT `#sql-13d9_4309ea_ibfk_1`
 FOREIGN KEY (`seller_id`) REFERENCES `accounts` (`id`) ON DELETE SET NULL ON UPDATE CASCADE)

ALTER TABLE market_transactions ADD FOREIGN KEY (buyer_id) REFERENCES 
accounts (id) ON DELETE SET NULL ON UPDATE CASCADE;

Query OK, 128 rows affected (0.09 sec)
Records: 128  Duplicates: 0  Warnings: 0