主题：用代码建立关联出错

我今天用代码建立关联时出现这个错误，一般是什么原因，要怎么解决？多谢！

此主题相关图片如下：6i(3y74o61n{lbj27%05.jpg

代码如下：

Dim wlb As DataTable
Dim ids As String = "11,12,13,14"
Dim cmd As New SQLCommand
cmd.C
Dim lm As String
For Each lmc As DataCol In DataTables("物料信息表").DataCols
    If lmc.name.StartsWith("别名") = True Then
        If lm = "" Then
            lm = lmc.name
        Else
            lm = lm & "," & lmc.name
        End If
    End If
Next
lm = lm & ",[_Identify],[产品名称],[保质系数]"
cmd.CommandText = "SELECT " & lm & " F rom {物料信息表} where _Identify in (" & ids & ")"
wlb = cmd.ExecuteReader()
wlb.DataCols.Add("code", Gettype(Integer), "[_Identify]")

Output.show(wlb.DataRows(0)("code"))

If DataTables.Contains("送货单") = False Then
    Dim dtb As New DataTableBuilder("送货单")
    dtb.AddDef("产品名称", Gettype(String), 50)
    dtb.AddDef("货品档案", Gettype(String), 150)
    dtb.AddDef("供应商", Gettype(String), 150)
    dtb.AddDef("包装规格", Gettype(String), 150)
    dtb.AddDef("产品数量", Gettype(Double))
    dtb.AddDef("产品销售价", Gettype(Double))
    dtb.AddDef("金额", Gettype(Double))
    dtb.AddDef("件数", Gettype(String), 20)
    dtb.AddDef("订单编号", Gettype(String), 200)
    dtb.AddDef("产品批号", Gettype(String), 200)
    dtb.AddDef("生产日期", Gettype(Date))
    dtb.AddDef("保质期", Gettype(Date))
    dtb.AddDef("产品", Gettype(String), 50)
    dtb.AddDef("标记", Gettype(Integer))
    dtb.Build()
   
End If

If Relations.Contains("shs") = False Then
    Relations.Add("shs",wlb.DataCols("code"),DataTables("送货单").DataCols("标记"))
End If

 

Output.show(wlb.DataRows(0)("code")) 的值是正常的