private static void CopyForeignKeyConstraint(
DbDatabaseMetadata database, DbTableMetadata toTable,
DbForeignKeyConstraintMetadata fk)
{
Contract.Requires(toTable != null);
Contract.Requires(fk != null);
var newFk = new DbForeignKeyConstraintMetadata
{
DeleteAction = fk.DeleteAction,
Name =
database.Schemas.Single().Tables.SelectMany(t => t.ForeignKeyConstraints).
UniquifyName(fk.Name),
PrincipalTable = fk.PrincipalTable
};
// Make sure all the dependent columns refer to columns in the newTable
SetAllDependentColumns(newFk, fk.DependentColumns, toTable.Columns);
if (!toTable.ContainsEquivalentForeignKey(newFk))
{
toTable.ForeignKeyConstraints.Add(newFk);
}
}
/// <summary>
/// Moves a foreign key constraint from oldTable to newTable and updates column references
/// </summary>
private static void MoveForeignKeyConstraint(
DbTableMetadata fromTable, DbTableMetadata toTable, DbForeignKeyConstraintMetadata fk)
{
Contract.Requires(fromTable != null);
Contract.Requires(toTable != null);
Contract.Requires(fk != null);
fromTable.ForeignKeyConstraints.Remove(fk);
// Only move it to the new table if the destination is not the principal table or if all dependent columns are not FKs
// Otherwise you end up with an FK from the PKs to the PKs of the same table
if (fk.PrincipalTable != toTable
||
!fk.DependentColumns.All(c => c.IsPrimaryKeyColumn))
{
// Make sure all the dependent columns refer to columns in the newTable
var oldColumns = fk.DependentColumns.ToArray();
fk.DependentColumns.Clear();
SetAllDependentColumns(fk, oldColumns, toTable.Columns);
if (!toTable.ContainsEquivalentForeignKey(fk))
{
toTable.ForeignKeyConstraints.Add(fk);
}
}
}
