CODEWITHSUNDEEP
c#asp.net
krishna mohan
krishna mohan

Reputation: 267

getting error in type casting - Input string was not in a correct format

I'm getting an error in this line int number = int.Parse(Days);

Input string was not in a correct format.

public string GetApprovedLimit(int CategoryId)
{
    SqlConnection connection = new SqlConnection(GetConnectionString());
    SqlCommand cmdLog = new SqlCommand();
    cmdLog.CommandType = CommandType.StoredProcedure;
    cmdLog.Connection = connection;
    cmdLog.Transaction = Trans;
    connection.Open();
    cmdLog.CommandText = "ApprovedDays";
    cmdLog.Parameters.AddWithValue("@CategoryId", CategoryId);
    string Days = cmdLog.ExecuteScalar() == null ? "1" : cmdLog.ExecuteScalar().ToString();
    connection.Close();
    int number = int.Parse(Days);
    Days = (number + 20).ToString(); // Added extra 20 days for late link submission
    return Days;
}

stored procedure:

Create Proc [dbo].[ApprovedDays]
(
    @CategoryId int
)
as begin

select ApprovedDays from tbl_Category where CategoryId=@CategoryId

end
GO

Upvotes: 0

Views: 192

Answers (2)

Tim Schmelter
Tim Schmelter

Reputation: 460018

  • If the row does not exist the result of cmdLog.ExecuteScalar() is null, no problem.
  • If the row exists but has NULL in this column, the result of cmdLog.ExecuteScalar() is DBNull.Value, DBNull.Value.ToString() returns an empty string which causes your exception.

Instead you should cast it to the corect type which seems to be an int:

int days = 1;
object obj = cmdLog.ExecuteScalar();
if(obj != null && DBNull.Value != obj)
{
    days = (int) obj;
}

Apart from that, the conditional operator executes the query twice. Store it in a variable.

Upvotes: 1

shreesha
shreesha

Reputation: 1881

From your question it looks like you are trying to parse an empty string.
Things you can try

int number = string.IsNullOrEmpty(days) ? 0 : int.Parse(days);

or

     if (int.TryParse(days, out number))
        {// Conversion succeeded}
     else
       {
         //failed
        }

MSDN says:int.TryParse Converts the string representation of a number to its 32-bit signed integer equivalent. A return value indicates whether the conversion succeeded

Upvotes: 1

Related Questions