Question

I have this public DataTable that I am trying to run an sql query in, but the dang thing wont work…

public DataTable get_OrderTransaction_Master_ByOrderID(Int64 orderID)
    {
        cn = new SqlConnection(objCommon.IpcConnectionString);
        cmd = new SqlCommand("select * from dbo.OrderTransaction_Master where orderID = " + orderID, cn);
        cmd.CommandType = CommandType.Text;
        cn.Open();
        cmd.ExecuteNonQuery();
        cn.Close();
    }

I get a red line under get_OrderTransaction_Master_ByOrderID saying

Error   3   'OrderTransaction_Master.get_OrderTransaction_Master_ByOrderID(long)': not all code paths return a value    C:\IPC\App_Code\OrderTransaction_Master.cs  32  22  http://localhost/ipc/

What Am I doing wrong?

Answer 1

The return type of your method is a DataTable, but you don’t have a return statement in your method. You are also executing cmd.ExecuteNonQuery(), where you should be doing cmd.ExecuteReader() and loading a DataTable

public DataTable get_OrderTransaction_Master_ByOrderID(Int64 orderID)
{
    DataTable dt = new DataTable();
    using(var cn = new SqlConnection(objCommon.IpcConnectionString))
    {
        using(var cmd = new SqlCommand(
            "select * from dbo.OrderTransaction_Master where orderID = " + orderID, cn))
        {
            cmd.CommandType = CommandType.Text;
            cn.Open();
            using(SqlDataReader reader = cmd.ExecuteReader())
            {
                dt.Load(reader);            
                return dt;
            }
        }
    }
}

I put the SqlConnection, SqlCommand and SqlDataReader in using statements. This will properly dispose of the objects (close the connections, etc) once the using statement is exited.