您收到此错误的原因是：



，让你的桌子有两排：

row1-> checklist_code = code1，order_no = order1，checklist_name = name1

row2-> checklist_code = code2，order_no = order2，checklist_name = name2





现在，你试图用输入（code2，name1）搜索当前表，并获得空结果（否则你的部分条件）



之后，当代码尝试更新表时，它显示违反主键的错误，因为您正在使用现有主键的值更新主键。[在您的其他部分条件中]



i认为你明白你犯了错误。

You getting this Error because:

let, your table has two rows:
row1-> checklist_code=code1,order_no=order1,checklist_name=name1
row2->checklist_code=code2,order_no=order2,checklist_name=name2


now, you are trying to search the current table with input(code2,name1),and getting empty result(else part of your condition)

after that, when the code trying to update the table, it's showing the error of violation of Primary key because you are updating the primary key with the value of an existing primary key.[in your else part condition]

i think you got the point where you made a mistake.

protected void checklist_modalpopup_save_Click(object sender, EventArgs e)
    {
        string c="", d="";
        connection();
        amicassaCon.Open();
        SqlCommand check = new SqlCommand("SELECT checklist_code, order_no FROM checklists Where checklist_name ='" + lblchecklist_popup_name.Text + "' AND checklist_code='" + lblchecklist_popup_code .Text+ "'", amicassaCon);
        SqlDataReader rd = check.ExecuteReader();
        while (rd.Read())
        {
            c = rd[0].ToString();
            d = rd[1].ToString();
 
        }
        rd.Close();
        amicassaCon.Close();
        if (c == lblchecklist_popup_code.Text || d == lblchecklist_popup_orderno.Text)
        {
            ScriptManager.RegisterStartupScript(this, this.GetType(), "popup", "alert('Error: Checklist Code/ Order Number have a duplicate in database!');", true);
            checklist_popup.Show();
        }
        else
        {

//Check here..where the table has any rows with updated checklist_code(lblchecklist_popup_code.Text)???
int no=GetNumOfRows_From_checklists("select * from checklists where checklist_code='" + lblchecklist_popup_code .Text+ "'");

if(no==0)
{

connection();
amicassaCon.Open();
SqlCommand cmd = new SqlCommand("UPDATE checklists SET checklist_code='" + lblchecklist_popup_code.Text + "',order_no='" + lblchecklist_popup_orderno.Text + "',checklist_status='" + rrd_checklist_status.SelectedValue + "',  checklist_type='" + rrdchecklist_popup_type.SelectedValue + "' WHERE checklist_name = '" + lblchecklist_popup_name.Text + "'", amicassaCon);
 SqlDataReader dr = cmd.ExecuteReader();

 dr.Close();
 amicassaCon.Close();
}
else
{
 ScriptManager.RegisterStartupScript(this, this.GetType(), "popup", "alert('Error: Updated Checklist Code have a duplicate in table.Try different Checklis Code !');", true);
}
}
connection();
checklist();

    }

public int GetNumOfRows_From_checklists(string query)
{

int NumRows=0;
try
{
DataTable dt=new DataTable();
connection();
amicassaCon.Open();
SqlCommand  cmd=new SqlCommand(query,amicassaCon); 
SqlDataAdapter da=new SqlDataAdapter(cmd);
da.Fill(dt);
if(dt.Rows.Count>0)
{
NumRows=dt.Rows.Count;
}
else
{
NumRows=0;
}

}
catch(exception e1)
{
NumRows=-1;
}
return NumRows;

}

原因可能是你的 checklist_name 得到不同的行结果。***有主键在哪里条件（建议）。



重写你的更新查询

Hi,

Reason may be your checklist_name getting different row result. Better to have primary key in where condition(suggestion).

Rewrite your update query

else
        {
            connection();
            amicassaCon.Open();
            SqlCommand cmd = new SqlCommand("UPDATE checklists SET order_no='" + lblchecklist_popup_orderno.Text + "',checklist_status='" + rrd_checklist_status.SelectedValue + "',  checklist_type='" + rrdchecklist_popup_type.SelectedValue + "' WHERE checklist_name = '" + lblchecklist_popup_name.Text + "' AND checklist_code='" + lblchecklist_popup_code .Text+ "'", amicassaCon);
            SqlDataReader dr = cmd.ExecuteReader();
            dr.Close();
            amicassaCon.Close();
        }