C＃SQL查询结果到文本框

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;
}

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