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();
}