public static void AddUniqueConstr(this ITransformationProvider migration, string table, params string[] columns)
{
string name = migration.UniqueConstraintName(table, columns);
migration.AddUniqueConstraint(name, table, columns);
}
public override void Execute(ITransformationProvider provider)
{
provider.AddUniqueConstraint(Name, Table.Name,
Columns.Select(x => x.Name).ToArray());
}