CODEWITHSUNDEEP
c#asp.netsql-server
Lenonor
Lenonor

Reputation: 47

How to modify retrieve from dataset/database

I am a beginner to this so I am trying an example to understand so I really appreciate your help.

I have the following web application structure:

enter image description here

I have the following code for clicking the button "save" which saves the text written in the 3 text boxes into the 3 fields of the table Trial in database:

protected void AddProgramButton_Click(object sender, System.EventArgs e)
{
    DataBinder ds = new DataBinder();
    sqlcon.Open();
    SqlCommand sqlcmd = new SqlCommand("INSERT INTO Trial VALUES (@FirstColumn, @SecondColumn , @ThirdColumn)", sqlcon);
    sqlcmd.Parameters.AddWithValue("@FirstColumn", RadTextBox1.Text);
    sqlcmd.Parameters.AddWithValue("@SecondColumn", RadTextBox2.Text);
    sqlcmd.Parameters.AddWithValue("@ThirdColumn", RadTextBox3.Text);

    sqlcmd.ExecuteNonQuery();
    //   lbl.Visible = true;
    sqlcon.Close();
}

My question is ::

The column FirstColumn in the table Trial is primary key field. So, I don't want to save the data into the database directly , BUT I want it to first check the value I entered in RadTextBox1 and see if it exists in the database or not ::

How can I do that ? I have been searching a lot but it is so confusing as I just started learning this. I reallyy appreciate your help.

Upvotes: 0

Views: 69

Answers (1)

gkrishy
gkrishy

Reputation: 756

You can use datareader for this,

if(RadTextBox2.Text!=""||RadTextBox3.Text!="")
{
RadTextBox2.Text="";
RadTextBox3.Text="";
}
SqlConnection con = new SqlConnection("Your connection");
con.Open();
SqlCommand cmd = new SqlCommand("Select * from Trial where FirstColumn = '"+RadTextBox1.Text+"'",con);
SQlDataReader dr = cmd.ExecuteReader();
while(dr.Read())
{
  if(dr.HasRows())
  {

     RadTextBox2.Text = dr.GetString(1);
     RadTextBox3.Text = dr.GetString(2);  
  }
  else
  {


  }
}
con.Close();

It will come on your RadTextBox1 change event.Make sure your RadTextBox1 autopostback property set to true.

Upvotes: 1

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