Question

我是ASP.NET MVC和Sql Server的新手尝试插入表1的第二步以从表1列y更新表2列x。更新其问题会更新整个列x

我的桌子：台式车（CarId 汽车模型颜色牌照板里程表）

表JobInfo （作业ID 工作号日期开始位置目的地里程表内径计停车处 CarId 用户ID）

更新Car Set CarOdometer =（从JobInfo中选择TOP 1 EndOdometer，其中CarId =通过EndOdometer DESC排序Car.CarId ORDER）

从JobInfo更新Car set Car.CarOdometer = JobInfo.EndOdometer，其中JobInfo.carId =（SELECT IDENT_CURRENT（JobInfo.CarId））;

试图使用内部联接但不起作用

            string query1 = "INSERT INTO JobInfo (JobNum,Date,StartLocation,Destination,EndOdometer,Parking,CarId,StartOdometer)" +
                                                  "VALUES(@JobNum,@Date,@StartLocation,@Destination,@EndOdometer,@Parking,@CarId,@StartOdometer)";


            string query2 = "Update Car SET Car.CarOdometer = (Select top 1 JobInfo.EndOdometer FROM JobInfo INNER JOIN Car ON JobInfo.CarId = Car.CarId "+
                             "ORDER BY JobInfo.EndOdometer desc) WHERE Car.CarId = Car.CarId";
            sqlCon.Open();
            var sqlCmd1 = new SqlCommand(query1, sqlCon);
            var sqlCmd2 = new SqlCommand(query2, sqlCon);

            sqlCmd1.Parameters.AddWithValue("@JobNum", jobModel.JobNum);
            sqlCmd1.Parameters.AddWithValue("@Date", jobModel.Date.ToString());
            sqlCmd1.Parameters.AddWithValue("@StartLocation", jobModel.StartLocation);
            sqlCmd1.Parameters.AddWithValue("@Destination", jobModel.Destination);
            sqlCmd1.Parameters.AddWithValue("@EndOdometer", jobModel.EndOdometer);
            sqlCmd1.Parameters.AddWithValue("@Parking", Convert.ToDecimal(jobModel.Parking));
            sqlCmd1.Parameters.AddWithValue("@CarId", Convert.ToInt32(jobModel.CarId));
            sqlCmd1.Parameters.AddWithValue("@StartOdometer", Convert.ToInt32(jobModel.StartOdometer));
            //Updating CarOdometer from EndOdometer
            sqlCmd2.Parameters.AddWithValue("@CarOdometer", Convert.ToInt32(jobModel.CarOdometer));


            sqlCmd1.ExecuteNonQuery();
            sqlCmd2.ExecuteNonQuery();

仅更新CarId = 1中的CarOdometer或将取决于CarId的CarOdometer应该更改，而不是所有记录

谢谢您的时间

Answer 1

如果除了JobInfo表中包含的那些记录外，您无需更改所有记录，可以对其进行检查：

UPDATE Car SET CarOdometer = (SELECT TOP 1 EndOdometer FROM JobInfo 
               WHERE CarId = Car.CarId ORDER BY EndOdometer DESC) 
       WHERE EXISTS (SELECT TOP 1 EndOdometer FROM JobInfo 
                    WHERE CarId = Car.CarId ORDER BY EndOdometer DESC)

从表1列y

1 个答案: