err:=u.db(ctx).Model(&relation.UserModel{}).Select("DATE(create_time) AS date, count(1) AS count").Where("create_time >= ? and create_time < ?",start,end).Group("date").Find(&res).Error
err:=u.db(ctx).Model(&relation.UserModel{}).Select("DATE(create_time) AS date, count(1) AS count").Where("create_time >= ? and create_time < ?",start,end).Group("date").Find(&res).Error