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 · Accepted 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;     }

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;
}