Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load ds = New DataSet("さんぷる") ds.CaseSensitive = True ds.EnforceConstraints = False Dim dt1 As DataTable = Createクエリ1() ds.Tables.Add(dt1) '自前で結合列を用意 Dim col As DataColumn = dt1.Columns.Add("消費税課税と消費税申告料の結合", GetType(String)) For Each row As DataRow In dt1.Rows Dim s As String Select Case row("消費税課税") Case 消費税課税.免税 s = "(免)" Case 消費税課税.原則課税 s = "(原)" Case 消費税課税.簡易課税 s = "(簡)" Case Else s = "" End Select row(col) = s & String.Format("{0:N0}", row("消費税申告料")) row.AcceptChanges() Next ds.EnforceConstraints = True 'これはデザイン時に行っても OK InitGrid() End Sub