Jerry,

Looks to me like you didn't actually instantiate your prop_MyDataSet object in Class1. You need to have the following line in there somewhere ...

    prop_myDataSet = new DataSet();

~~Bonnie


>Using C#.
>
>I am trying to create 2 classes. In class1, I am trying to define my OleDb connection vars/fields.
>
>In class2, I am trying to use these fields from class1 to query the datasource. However, when I run the project, I get the following error: "Object reference not set to an instance of an object"
>
>Here is what my C# code looks like: (Pseudo Code)
>

>///////////////////////////////////////////////////////////
>public class class1
>///////////////////////////////////////////////////////////
>//Fields:
>	public string prop_strAccessConn;
>	public string prop_strAccessSelect;
>	public DataSet prop_myDataSet;
>	public string prop_ctable;
>	public string prop_myAccessConn;
>	public string prop_myAccessCommand;
>	public string prop_myDataAdapter;
>public class1()  //Default constructor:
>	prop_strAccessConn =
>                  "Provider=VFPOLEDB.1;Data Source=C:\\APPS\\MYDBC.DBC"
>	prop_strAccessSelect = "SELECT * FROM mytable";
>
>	OleDbConnection prop_myAccessConn = new OleDbConnection
>               (prop_strAccessConn);
>	OleDbCommand prop_myAccessCommand = new OleDbCommand
>               (prop_strAccessSelect,prop_myAccessConn);
>	OleDbDataAdapter prop_myDataAdapter = new OleDbDataAdapter
>               (prop_myAccessCommand);
>
>public static void Main ()
>
>///Call class2 for processing.
>class2.processit();
>
>
>///////////////////////////////////////////////////////////
>public class class2
>///////////////////////////////////////////////////////////
>public static void processit ()
>
>Console.WriteLine("Write output to the console.");
>class1 oclass1 = new class1();   //Create object reference.
>oclass1.prop_myDataSet.Tables.Add("mytable");   //I get error here.

>
>
>I can't get the above example to work. However the following example does work but I would like to separate and make the OleDb vars accessible to other classes without redefining the vars.
>

>///Working example. Pseudo code.
>//////////////////////////////
>public class class1
>//////////////////////////////
>public static void Main ()
>string strAccessConn = "Provider=VFPOLEDB.1;Data Source=C:\\APPS\\CTRAK6\\CTTRAK.DBC"
>
>string strAccessSelect = "SELECT * FROM mytable";
>
>// Create the dataset and add the ctghead table to it:
>DataSet myDataSet = new DataSet();
>myDataSet.Tables.Add("mytable");
>
>// Create Access objects:
>OleDbConnection myAccessConn = new OleDbConnection(strAccessConn);
>OleDbCommand myAccessCommand = new OleDbCommand(strAccessSelect,myAccessConn);
>OleDbDataAdapter myDataAdapter = new OleDbDataAdapter(myAccessCommand);
>
>myAccessConn.Open();
>

>etc... everything works!
>
>
>What am I doing wrong with regards to defining OleDb information in class1 and accessing those objects in another class to query a datasource?
>
>Thanks,
>
>Jerryt