public void UpdateRoles(long userId, RoleUser[] roleUsers, DbContext dbContext) { string sql = "delete from " + ImmsDbContext.GetEntityTableName <RoleUser>() + " where user_id = @p0"; dbContext.Database.ExecuteSqlCommand(sql, userId); foreach (RoleUser roleUser in roleUsers) { dbContext.Set <RoleUser>().Add(roleUser); } dbContext.SaveChanges(); }