C# SQL query result to textboxes

Question

Newbie here, working on converting a little program I had in python/sqlite to C#/SQL Server. I'm having a bit of an issue with getting a SQL query to write its results to two textboxes (textBox1 and textBox2) based upon the selection of a combobox (which does populate correctly, by the way). Here's my attempted code, just need the last bit that writes the result to the textboxes:

 private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
 {
 textBox1.Clear();
 string selected = (this.comboBox1.SelectedIndex).ToString();
 var selected2 = from branches in branchesDataSet.branches
 where branches.branchCode == "selected"
 select new
 {
 branches.branchCode
 branches.branchName
 };

I've tried passing it to an array, to a list, just can't seem to get it to give the result, just the identifier. Any help? Where am I going wrong?

Answer 1

What you have at the moment is an IQueryable<T> for some unpronounceable anonymous-type T. I assume, since you are using text-boxes, that you expect at most one row, so:

var row = selected2.FirstOrDefault();
if(row == null) {
 textBox1.Text = textBox2.Text = "n/a";
} else {
 textBox1.Text = row.branchCode;
 textBox2.Text = row.branchName;
}

• b0b: Thanks, modified my code, including an error I had with the selection (string selected = comboBox1.Text;), but I keep getting a n/a return. I know there's data, I just entered the data, and a SQL query gives me the data. Definitely on the right track though.
• Marc Gravell: @b0b heh; you probably mean: where branches.branchCode == selected, not where branches.branchCode == "selected". Note the quotes.
• b0b: You sir, are a genius. Something so simple! Comes from trying to translate from one language to another without the required experience.

Answer 2

Since you use textbox this mean you query one row:

var onerow= selected2.FirstOrDefault();
if(row == null) { textBox1.Text = textBox2.Text = "n/a";} 
else { textBox1.Text = onerow.branchCode; textBox2.Text = onerow.branchName; }

Hope this help you

• b0b: Thank you for just verbatimely repeating what Marc said.