C# 使用linq查询比较列与列

我遇到了一个我目前一直在解决的问题。例如：

EmployeeShiftID |     ShiftTime_Start     |     hiftTime_Stop     |     Name     | Emp_Start | Emp_Stop
                |(linked with foreign key)|    (linked with FK)   |              |           |
    1           |       0000              |         1000          |      Ken     |    0000   |    1000

这些数据显示在数据网格视图中，外键链接。换档启动和停止也与Emp_启动和停止相匹配。问题是，当我更新Emp_启动和停止时，换档时间_启动和停止与Emp_启动和停止不相比较，并在我尝试将Emp_启动和停止更改为0430和2100时保持为0000和1000

我在数据库中保存的时间类型是String而不是time。有人能帮我吗？我将展示我为它所做的任何代码

private void btnUpdate_Click(object sender, EventArgs e)
{
    using (testEntities Setupctx = new testEntities())
    {
        int ID = Int32.Parse(lblID.Text);
        var ESquery = (from es in Setupctx.employeeshifts
                       where es.EmployeeShiftID == ID
                       select es).First();

        ESquery.StartTime = txtStart.Text;
        ESquery.EndTime = txtStop.Text;
        ESquery.Date = txtDate.Text;
        Setupctx.SaveChanges();
        txtStart.Text = "";
        txtStop.Text = "";
        txtDate.Text = "";
        this.Edit_Employee_Shift_Load(null, EventArgs.Empty);
        MessageBox.Show("Employee's Shift Has Been Updated.");
    }
}


private void LoadAllEditEmpShift()
{
    using (testEntities Setupctx = new testEntities())
    {
        BindingSource BS = new BindingSource();
        var Viewemp = from ES in Setupctx.employeeshifts
                      join shifthour sh in Setupctx.shifthours on ES.ShiftHourID equals sh.idShiftHours
                      select new
                      {
                          ES.EmployeeShiftID,
                          ShiftHour_Start = sh.shiftTiming_start,
                          ShiftHour_Stop = sh.shiftTiming_stop,
                          ES.EmployeeName,
                          ES.StartTime,
                          ES.EndTime,
                          ES.Date
                      };

        BS.DataSource = Viewemp;
        dgvEmpShift.DataSource = BS;
    }
}

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您应该在btnUpdate\u Click方法中隐式更新shifthour对象的属性。

我认为它应该如下所示：

private void btnUpdate_Click(object sender, EventArgs e)
{
    using (testEntities Setupctx = new testEntities())
    {
        int ID = Int32.Parse(lblID.Text);
        var ESquery = (from es in Setupctx.employeeshifts
                       where es.EmployeeShiftID == ID
                       select es).First();
        var SHquery = (from sh in Setupctx.shifthours where sh.idShiftHours == ESQuery.ShiftHourID 
                      select sh).First();

        ESquery.StartTime = txtStart.Text;
        ESquery.EndTime = txtStop.Text;
        ESquery.Date = txtDate.Text;
        SHquery.shiftTiming_start = ESquery.StartTime;
        SHquery.shiftTiming_stop = ESquery.EndTime;
        Setupctx.SaveChanges();
        txtStart.Text = "";
        txtStop.Text = "";
        txtDate.Text = "";
        this.Edit_Employee_Shift_Load(null, EventArgs.Empty);
        MessageBox.Show("Employee's Shift Has Been Updated.");
    }
}

---

能给我举几个例子吗？