Error : ExecuteScalar Connection not initialised.

Question

Hi

public abstract class clscon
    {
        protected SqlConnection con = new SqlConnection();
        public clscon()
        {
            con.ConnectionString = ConfigurationManager.ConnectionStrings["cn"].ConnectionString;
        }
    }

    public class clscon1 : clscon
    {
        public void OpenConnection()
        {
            con.Open();
        }
    }

public Int32 GetAuto()
    {
        nsDal.clscon1 con1 = new nsDal.clscon1();
        con1.OpenConnection();

SqlCommand cmd = new SqlCommand();

        cmd.CommandText = "Select isnull(max(orgcod),0) from tborg";
        Int32 v_no = Convert.ToInt32(cmd.ExecuteScalar());
        cmd.Dispose();
        return v_no + 1;
    }

It is giving error "ExecuteScalar . Connection has not been initialised".

Vulpes · Answer

The problem here is that con1 isn't actually a SqlConnection object but an instance of the wrapper class clscon1. To get the connection object itself you'll need to add a method to that class as the field is protected: public abstract class clscon { protected SqlConnection con = new SqlConnection(); public clscon() { con.ConnectionString = ConfigurationManager.ConnectionStrings[cn].ConnectionString; } } public class clscon1 : clscon { public void OpenConnection() { con.Open(); } public SqlConnection GetConnection() { return con; } } public Int32 GetAuto() { nsDal.clscon1 con1 = new nsDal.clscon1(); SqlConnection conn = con1.GetConnection(); con1.OpenConnection(); SqlCommand cmd = new SqlCommand(); cmd.Connection = conn; cmd.CommandText = Select isnull(max(orgcod)0) from tborg; Int32 v_no = Convert.ToInt32(cmd.ExecuteScalar()); cmd.Dispose(); return v_no + 1; }

Muralidharan Deenathayalan · Answer

Before executesclar line add the below line. cmd.Connection = con1; Before executing the query You need assign the command.connection of your connnection. public Int32 GetAuto() { nsDal.clscon1 con1 = new nsDal.clscon1(); con1.OpenConnection(); SqlCommand cmd = new SqlCommand(); cmd.CommandText = Select isnull(max(orgcod)0) from tborg; cmd.Connection = con1; //make sure  the con1 is opened its database connection. Int32 v_no = Convert.ToInt32(cmd.ExecuteScalar()); cmd.Dispose(); return v_no + 1; }