/// <summary>
/// Gets the foreign key for the given properties that points to a given primary or alternate key. Returns null
/// if no foreign key is found.
/// </summary>
/// <param name="entityType"> The entity type to find the foreign keys on. </param>
/// <param name="property"> The property that the foreign key is defined on. </param>
/// <param name="principalKey"> The primary or alternate key that is referenced. </param>
/// <param name="principalEntityType">
/// The entity type that the relationship targets. This may be different from the type that <paramref name="principalKey" />
/// is defined on when the relationship targets a derived type in an inheritance hierarchy (since the key is defined on the
/// base type of the hierarchy).
/// </param>
/// <returns> The foreign key, or null if none is defined. </returns>
public static IMutableForeignKey FindForeignKey(
[NotNull] this IMutableEntityType entityType,
[NotNull] IProperty property,
[NotNull] IKey principalKey,
[NotNull] IEntityType principalEntityType)
{
Check.NotNull(entityType, nameof(entityType));
return(entityType.FindForeignKey(new[] { property }, principalKey, principalEntityType));
}
/// <summary>
/// Gets an existing relationship, or creates a new one if one is not already defined.
/// </summary>
/// <param name="entityType"> The entity type to get or add the foreign key to. </param>
/// <param name="properties"> The properties that the foreign key is defined on. </param>
/// <param name="principalKey"> The primary or alternate key that is referenced. </param>
/// <param name="principalEntityType">
/// The entity type that the relationship targets. This may be different from the type that <paramref name="principalKey" />
/// is defined on when the relationship targets a derived type in an inheritance hierarchy (since the key is defined on the
/// base type of the hierarchy).
/// </param>
/// <returns> The existing or newly created foreign key. </returns>
public static IMutableForeignKey GetOrAddForeignKey(
[NotNull] this IMutableEntityType entityType,
[NotNull] IReadOnlyList <IMutableProperty> properties,
[NotNull] IMutableKey principalKey,
[NotNull] IMutableEntityType principalEntityType)
{
Check.NotNull(entityType, nameof(entityType));
return(entityType.FindForeignKey(properties, principalKey, principalEntityType)
?? entityType.AddForeignKey(properties, principalKey, principalEntityType));
}
public static IMutableForeignKey?FindForeignKey(
[NotNull] this IMutableEntityType entityType,
[NotNull] IReadOnlyProperty property,
[NotNull] IReadOnlyKey principalKey,
[NotNull] IReadOnlyEntityType principalEntityType)
=> entityType.FindForeignKey(new[] { property }, principalKey, principalEntityType);
