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ASP.net adding items to a DropDownList VB code

In ASP.net I have a backend Access database.
On my WebForm, I have several DropDownLists.
I want to populate each of these with the unique items from
ecah column of Table1 in my backend database called GC.accdb.
What VB.net code would I use to do this?
I have learnt so far that the SQL code is "Select Distinct MyColumn From MyTable"

Dirk Haest

I would suggest to retrieve all the data at once (the complete table myTable)

And then use a select distinc for each column that you want to bind to a combobox
http://www.thescarms.com/dotnet/BindCombobox.aspx

Dim OleDbConnection As System.Data.OleDb.OleDbConnection
Dim OleDbSelectCommand As System.Data.OleDb.OleDbCommand

OleDbSelectCommand.CommandText = "SELECT * FROM myTable"
OleDbSelectCommand.Connection = OleDbConnection

       
Dim myDataAdapter As System.Data.OleDb.OleDbDataAdapter
myDataAdapter = New System.Data.OleDb.OleDbDataAdapter()

myDataAdapter .SelectCommand = OleDbSelectCommand

Dim myDataSet As System.Data.DataSet
 
myDataAdapter.Fill(myDataSet )

DataTable dt=SelectDistinct("myTable", myDataSet .tables("myTable"),"MyColumn ")








private bool ColumnEqual(object A, object B)
{

if ( A == DBNull.Value && B == DBNull.Value ) 
return true; 
if ( A == DBNull.Value || B == DBNull.Value ) 
return false; 
return ( A.Equals(B) ); 

}


public DataTable SelectDistinct(string TableName, DataTable SourceTable, string FieldName)
{ 
DataTable dt = new DataTable(TableName);
dt.Columns.Add(FieldName, SourceTable.Columns[FieldName].DataType);

object LastValue = null; 
foreach (DataRow dr in SourceTable.Select("", FieldName))
{
if ( LastValue == null || !(ColumnEqual(LastValue, dr[FieldName])) ) 
{
LastValue = dr[FieldName]; 
dt.Rows.Add(new object[]{LastValue});
}
}
if (ds != null) 
ds.Tables.Add(dt);
return dt;
}

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Murray Brown

ASKER

Hi. Thanks. Where do I put that code. It is not VB code

ASKER CERTIFIED SOLUTION

Dirk Haest

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Murray Brown

ASKER

I am lost...don't understand this

Murray Brown

ASKER

thanks