Very vegetable problem, ask everyone to help! Urgent!

keenlad

string select = "SELECT MIN (PhotoID) FROM Photo WHERE AlbumID = 1";
SqlCommand cmd = new SqlCommand (select, con);
object o = cmd.ExecuteScalar ();
con.Close ();
  if (o == null)
  {
        return 0;
  }
  else
 {
     return Convert.ToInt32 (o); Error: Object cannot be converted from DBNull to another type.

  }
After I set the breakpoint, I can be sure o is correct (o = 1), why is this ?? What should I do ???
Thank you everyone !!!

freeamway

Change to return Convert.ToInt32(o.ToString());

keenlad

No, return Convert.ToInt32(o.ToString()); There will be an exception of "the output string format is incorrect"!

摩羯可乐

Try this

        object o = m_SqlCommand.ExecuteScalar();
        if (Convert.ToString(o)== "")
        {
            Response.Write("dfsdfds");
        }
        else
        {
            Response.Write(Convert.ToInt32(o));
        }

3521565

else
{
     return Convert.ToInt32(o); Error: Object cannot be converted from DBNull to other types.

  }

is this OK
      return (int)o;

freeamway

What type are you returning?

my_veigh

object o = cmd.ExecuteScalar();
STRING P=O.TOSTRING();
con.Close();
  if (P == null)
  {
        return 0;
  }
  else
{
     return Convert.ToInt32(P); Error: Object cannot be converted from DBNull to other types.

  }

摩羯可乐

Didn't I write the code above for you? If your sql statement has no value, the return value is empty, so your judgment is wrong, no problem according to what I wrote above

mythsiva

string o = Convert.ToString(cmd.ExecuteScalar());
con.Close();
  if (o == "")
  {
        return 0;
  }
  else
{
     return Convert.ToInt32(o);

  }