please find the error

Durga Velusamy

I have following code its shows an error please some one find what mistake I have done.
Error at 9^th line as "Input string was not in a correct format".

private void button2_Click(object sender, EventArgs e)
{

int CustomerId=0;
int i=0;
SqlConnection con = new SqlConnection(@"server=CSE-PC; integrated security=true; Database=Bas");
con.Open();
SqlCommand com = new SqlCommand("select max(CustomerId) FROM DEVI", con);
CustomerId = int.Parse(com.ExecuteScalar().ToString());
/*Input string was not in a correct format.*/
if (i>0)
{
CustomerId = CustomerId + 1;
}
else
{
CustomerId = 001;
}
comboBox1.Items.Add("CustomerId");
i = i + 1;
MessageBox.Show("IdCreated");
con.Close();
}

4 Replies

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Syed Shanu11y ago
Accepted answer
The error is due to first time in your table there is no CurstomerID so it return empty value .when you convert empty value to integer it gives error.

try the below code.

   int CustomerId = 0;
            int i = 0;

            SqlConnection con = new SqlConnection(@"server=CSE-PC; integrated security=true; Database=Bas");
            con.Open();

            SqlCommand com = new SqlCommand("select max(CustomerId) FROM DEVI", con);
            if (com.ExecuteScalar().ToString() == "")
            {
                CustomerId = 0;
            }
            else
            {
                CustomerId = int.Parse(com.ExecuteScalar().ToString());
            }

            if (CustomerId > 0)
            {
                CustomerId = CustomerId + 1;
            }
            else
            {
                CustomerId = 001;
            }
0
Durga Velusamy11y ago
thank you to all of you.
0
Ankur Jain11y ago
Hi!
I am not sure why you would get this in v2.0 but not in previous versions. ExecuteScalar() is returning something that cannot be cast to an int, and thus you are seeing this error. So the first thing you can check is what ExecuteScalar is really returning. You can use the debugger, or output "ExecuteScalar().GetType().ToString()", and that will give you the type of what is being returned.
0
Michal Habalcik11y ago
you're clearly trying to parse some non-numeric string here:

CustomerId = int.Parse(com.ExecuteScalar().ToString());

put a break point there and check what is the ExecuteScalar actually returning.

If you are not really familiar with debuging, just print it to console to check out:

Console.WriteLine(com.ExecuteScalar().ToString())
0