you can try this code for retrieving all column’s name of sql table in single string in vb.net
Private Function GetColumnsName() As String
Dim dsColumnName As New DataSet
Dim Con As New SqlClient.SqlConnection(ConnectionString)
Con.Open()
Dim strSql As String = "SELECT column_name FROM INFORMATION_SCHEMA.Columns where TABLE_NAME = '" & TableName & "'"
Dim dAdapter As New SqlClient.SqlDataAdapter(strSql, Con)
dAdapter.Fill(dsColumnName)
Dim ColumnsName_String As String = ""
For i As Integer = 0 To dsColumnName.Tables(0).Rows.Count - 1
ColumnsName_String = ColumnsName_String & "," & dsColumnName.Tables(0).Rows(i).Item(0)
Next
If ColumnsName_String.StartsWith(",") Then
ColumnsName_String = ColumnsName_String.Remove(0, 1)
End If
Return ColumnsName_String
End Function