C＃注册系统调度冲突

Question

我在我的系统中有一个问题，我想在将值插入数据库后发生错误。这是我更好解释的例子。

我有两张表是Enlistment和Subject，这是样本值。现在

我的问题是我想把和我的错误的时间将是例如相同或冲突： 我将广告在入伍表，这是一个值。

现在，这将创建一个错误，因为你可以对主题表看， offerNo = 102有开始时间，结束时间，并插入值的天数在入伍表中的值相同。然后，如果它不是相同的值，它只会插入表中而不会出现错误。你能给我一些代码，就如何解决这个问题，谢谢大家的帮助

这是我precedure代码

CREATE PROCEDURE [dbo].[addSubject] 
(
@newStudID int, 
@newofferNo int 
) 
AS 
BEGIN 
BEGIN TRANSACTION 

declare @newStart datetime 
set @newStart = (select StartTime from Subject where offerNo = @newofferNo) 
declare @newEnd datetime 
set @newEnd = (select EndTime from Subject where offerNo = @newOfferNo) 
declare @newDays varchar(50) 
set @newDays = (select StudDays from Subject where offerNo = @newOfferNo) 

insert into Enlistment values(@newStudID, @newStudID, @newOfferNo, @newStart, @newEnd, @newDays) 

UPDATE Subject 
SET Capacity = Capacity - 1 
WHERE offerNo = @newofferNo 

COMMIT TRANSACTION 
END 

现在，这是我在前端

 conn = koneksyon.getConnect(); 
     conn.Open(); 
     cmd = new SqlCommand("Select a.offerNo from Enlistment a, Subject b where a.offerNo = b.offerNo AND a.offerNo ='" + textEnrollOfferNo.Text + "' AND a.studID = '" + textEnrollID.Text + "'", conn); 
     dr = cmd.ExecuteReader(); 
     while (dr.Read()) 
     { 
      offerNo = dr[0].ToString(); 
     } 
     dr.Dispose(); 

     cmd = new SqlCommand("Select offerNo,Capacity,StartTime, EndTime,StudDays from Subject where offerNo ='" + textEnrollOfferNo.Text + "'", conn); 
     dr = cmd.ExecuteReader(); 
     while (dr.Read()) 
     { 
      offNo = dr[0].ToString(); 
      capacity = dr[1].ToString(); 
      start = dr[2].ToString(); 
      end = dr[3].ToString(); 
      day = dr[4].ToString(); 

     } 
     dr.Dispose(); 

     cmd = new SqlCommand("Select StartTime, StudDays from Enlistment where StudDays = '" + day + "'", conn); 
     dr = cmd.ExecuteReader(); 
     while (dr.Read()) 
     { 
      START = dr[0].ToString(); 
      DAY = dr[1].ToString(); 
     } 
     dr.Dispose(); 


     cmd.Dispose(); 
     conn.Close(); 
     if (textEnrollOfferNo.Text == "") 
     { 
      MessageBox.Show("Input Offer No.", "ERROR", MessageBoxButtons.OK, MessageBoxIcon.Error); 
      textEnrollOfferNo.Clear(); 
      textEnrollOfferNo.Focus(); 
     } 
     else if (textEnrollOfferNo.Text == offerNo) 
     { 
      MessageBox.Show("Cannot insert duplicate schedules", "ERROR", MessageBoxButtons.OK, MessageBoxIcon.Error); 
      textEnrollOfferNo.Clear(); 
      textEnrollOfferNo.Focus(); 
     } 
     else if (offNo != textEnrollOfferNo.Text) 
     { 
      MessageBox.Show("Offer No doesn't exist!", "ERROR", MessageBoxButtons.OK, MessageBoxIcon.Error); 

      textEnrollOfferNo.Clear(); 
      textEnrollOfferNo.Focus(); 
     } 
     else if (textEnrollOfferNo.Text == offNo && Convert.ToInt32(capacity) == 0) 
     { 
      MessageBox.Show("Subject is closed!", "ERROR", MessageBoxButtons.OK, MessageBoxIcon.Error); 
      textEnrollOfferNo.Clear(); 
      textEnrollOfferNo.Focus(); 
     } 
     else if((textEnrollOfferNo.Text != offerNo && START == start && DAY == day) || (offerNo != textEnrollOfferNo.Text && start == START && day == DAY) || (textEnrollOfferNo.Text != offerNo && START == start && day == DAY) || (textEnrollOfferNo.Text != offerNo && start == START && DAY == day)) 
     { 
      MessageBox.Show("Subject is conflict!", "ERROR", MessageBoxButtons.OK, MessageBoxIcon.Error); 
      textEnrollOfferNo.Clear(); 
      textEnrollOfferNo.Focus(); 
     } 
     else 
     { 
      //Button Add Subject for Student 
      conn = koneksyon.getConnect(); 
      conn.Open(); 
      cmd = new SqlCommand("AddSubject", conn); 
      cmd.CommandType = CommandType.StoredProcedure; 


      cmd.Parameters.Add("@newStudID", SqlDbType.Int).Value = Convert.ToInt32(textEnrollID.Text); 
      cmd.Parameters.Add("@newofferNo", SqlDbType.Int).Value = Convert.ToInt32(textEnrollOfferNo.Text); 

      cmd.ExecuteNonQuery(); 
      conn.Close(); 
      cmd.Dispose(); 

      MessageBox.Show("Added Successfully! ", "SUCCESS", MessageBoxButtons.OK, MessageBoxIcon.Information); 
      conn = koneksyon.getConnect(); 
      conn.Open(); 
      dataGridView1.Rows.Clear(); 
      cmd = new SqlCommand("Select a.offerNo,b.subj,b.description,b.units,b.StartTime, b.EndTime,b.room,b.StudDays from Enlistment a, Subject b where a.offerNo = b.offerNo AND a.studID ='" + textEnrollID.Text + "' ORDER BY a.StudDays, a.StartTime", conn); 
      dr = cmd.ExecuteReader(); 
      while (dr.Read()) 
      { 
       string startTime = dr[4].ToString(); 
       string EndTIme = dr[5].ToString(); 
       DateTime start1 = DateTime.Parse(startTime); 
       DateTime end1 = DateTime.Parse(EndTIme); 

       string Time = start1.ToString("h:mm") + " - " + end1.ToString("h:mm tt"); 

       dataGridView1.Rows.Add(dr[0], dr[1], dr[2], dr[3], Time, dr[6], dr[7]); 
      } 
      dr.Dispose(); 
      cmd.Dispose(); 
      conn.Close(); 

      conn = koneksyon.getConnect(); 
      conn.Open(); 

      cmd = new SqlCommand("Select sum(b.units) from Enlistment a, Subject b where a.offerNo = b.offerNo AND a.studID ='" + textEnrollID.Text + "'", conn); 
      dr = cmd.ExecuteReader(); 
      while (dr.Read()) 
      { 
       textTotalUnits.Text = dr[0].ToString(); 
      } 
      dr.Dispose(); 
      conn.Close(); 
      cmd.Dispose(); 
     } 
     dr.Dispose(); 
     cmd.Dispose(); 
     conn.Close(); 

Answer 1

代码

不知道你如何使用C＃代码，你用C＃连接数据库的技术是什么？ （EF？L2S？，OR映射，原始的SQL？...等），但你可以检查使用存储过程或原始查询是否有使用此查询

declare @studentId int = 1000, 
     @offerId int = 102, 
     @existOffer int 
select @existOffer = t.OfferNo 
from Subject c, Subject t 
where c.OfferNo = @offerId 
and c.StartTime = t.StartTime 
and c.Days = t.Days 
and c.OfferNo!= t.OfferNo 
and exists(
    select 1 
    from Enlistment e 
    where e.OfferNo = t.OfferNo and e.StudentID = @studentId 
) 

现在发生任何冲突，如果@existOffer不为空，这意味着存在冲突，并且您可以显示与最终用户存在冲突的消息。

希望这将帮助你