列不允许空值 [英] Column does not allow nulls

问题描述

请看看我下面的code，告诉我在哪里，我错了。

Please have a look at my code below and tell me where i am going wrong.

case "particulars.aspx":
   dt = JobCardManager.GetParticularsByJobId(id);
   hidJobId.Value = id.ToString();
   if (dt != null && dt.Rows.Count > 0)
   {
      gvParticulars.DataSource = dt;
      gvParticulars.DataBind();
   }
   else
   {
      **dt.Rows.Add(dt.NewRow());**
      gvParticulars.DataSource = dt;
      gvParticulars.DataBind();

      int TotalColumns = gvParticulars.Rows[0].Cells.Count;
      gvParticulars.Rows[0].Cells.Clear();
      gvParticulars.Rows[0].Cells.Add(new TableCell());
      gvParticulars.Rows[0].Cells[0].ColumnSpan = TotalColumns;
      gvParticulars.Rows[0].Cells[0].Text = "No Record Found";
   }

   ddlJobs.Enabled = false;
   gvParticulars.ShowFooter = true;
   break;

我想实现的是，在情况下，当 DT 没有任何行，我需要显示在页脚中的新行，管制已添加在页脚。我的INSERT，UPDATE和添加新过程中的所有从电网本身进行。

What I want to achieve is that in case when the dt don't have any rows, I need to display a new row in the footer, controls are already added in footer. My insert update and add new process all are carried out from grid itself.

所以，如果，如​​果我的数据表来空，然后在星号线，我得到的错误，列不允许空。凡在数据库中的所有列都允许空复选框被选中。请大家帮帮忙。

So in case if my datatable comes null, then at the starred line, I am getting the error, "Column does not allow null". Where in database all columns have Allow Null checkboxes are checked. Please help.

[更新]

我不retriving在查询中的主键。只有表的编辑区域。

I am not retriving primary key in the query. Only the editable parts of the table.

推荐答案

您可能想读取架构信息，当您填写的数据集。我不知道这是否会解决您的问题，但我怀疑它会的。如果没有模式，您的数据表将不知道该列是否接受空或不是。<​​/ P>

You might want to read the schema information when you fill the dataset. I'm not sure whether this would solve your problem, but I suspect it will. Without the schema, your datatable won't know whether the column accepts null or not.

da.FillSchema(ds, SchemaType.Source);
da.Fill(ds);

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