Question

Using linq2sql I’m trying to take the string in txtOilChange and update the oilChange integer in the car table of the white fusion.

I know my code below is wrong but what do I need to change?

using (DataClasses1DataContext db = new DataClasses1DataContext())
{
var o = (from c in db.cars
where c.carDesc == "White Fusion"
select c).First();

txtOilChange.Text = o.oilChange.ToString();

db.SubmitChanges();
}

Answer 1

If you’re trying to update the record it looks like the assignment statement is reversed.

This:

txtOilChange.Text = o.oilChange.ToString();

Should be:

o.oilChange = int.Parse(txtOilChange.Text);

For better error handling consider using the TryParse method:

int oilChangeValue;
if (int.TryParse(txtOilChange.Text, out oilChangeValue))
{
    o.oilChange = oilChangeValue;
    db.SubmitChanges();
} 
else
{
    // invalid value
}