ALTER TABLE Syntaxe: ALTER TABLE `nomtable` ADD CONSTRAINT `nom_contrainte` FOREING KEY (`champ1`, `champ2`) REFERENCE `nomtable2` (`champ3`) ON DELETE CASCADE ON UPDATE NO ACTION, ADD CONSTRAINT ...;
ALTER TABLE Syntaxe: ALTER TABLE `nomtable` ADD CONSTRAINT `nom_contrainte` FOREING KEY (`champ1`, `champ2`) REFERENCE `nomtable2` (`champ3`) ON DELETE CASCADE ON UPDATE NO ACTION, ADD CONSTRAINT ...;