The Employees table has a DistrictID column that must always refer to an existing row in the Districts table. What enforces this rule?
La table Employés possède une colonne IDDistrict qui doit toujours désigner une ligne existante de la table Districts. Qu'est-ce qui impose cette règle ?
Answers
AAn index on the Employees table's name column, sorted alphabeticallyUn index sur la colonne du nom de la table Employés, trié par ordre alphabétique
BA foreign key constraint from Employees.DistrictID to DistrictsUne contrainte de clé étrangère de Employés.IDDistrict vers Districts
CA view on the Districts tableUne vue sur la table Districts
DA trigger that emails the DBAUn déclencheur qui envoie un e-mail à l'administrateur de base de données
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