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C # sql operator doesn't seem to work

Hello good afternoon. I have a small question on how to describe sql / C #, I cannot figure out why my code is not working.

if (Combo_List.Text == "What")
{
   listView1.Items.Clear();
   myds.Clear();
   mydaEvents.SelectCommand = myconn.CreateCommand();
   mydaEvents.SelectCommand.CommandText = "select * from Eventstbl where What like '@what%'";
   mydaEvents.SelectCommand.CommandType = CommandType.Text;
   mydaEvents.SelectCommand.Parameters.Add("@what", SqlDbType.NVarChar, 2000, "What").Value = text_Search.Text;
   mydaEvents.Fill(myds, "Eventstbl");

   foreach (DataRow item in myds.Tables["Eventstbl"].Rows)
   {
       ListViewItem items = new ListViewItem(item["EventsID"].ToString());
       items.SubItems.Add(item["What"].ToString());
       listView1.Items.Add(items);
   }
}

@ what% won't work, but when I put "%" all items that start with the letter a are shown in my list view1. I don't know how to fix this problem. Help me please. Thank you in advance.

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2 answers


Try the following:

mydaEvents.SelectCommand.CommandText = "select * from Eventstbl where What like @what + '%'";


The text inside the quotes will be treated as ... text - you want your parameter to be interpreted as its string value, so you need to move it.

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I guess the problem is what is being '@what%'

treated as a literal and not being replaced with the value of your parameter.



Try doing @what + '%'

this instead.

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