Question

I have a funny problem. I want to execute this query, but this error happen:

“Specified cast is not valid.”

Can any body help me?

here is my code:

 string connStr = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
        SqlConnection sqlconn = new SqlConnection(connStr);
        SqlCommand sqlcmd = new SqlCommand();
        sqlcmd = new SqlCommand("SELECT max(ID) FROM AddNews ", sqlconn);

        sqlconn.Open();
        int ID = ((int)sqlcmd.ExecuteScalar());
        sqlconn.Close();

Answer 1

There is a case the you may not have results and the return can be null.

You better try

int? MaxID = sqlcmd.ExecuteScalar() as int?;

and check if the MaxID is not null.