数据类型 ntext 和 varchar 在 equal to 运算符中不兼容。 - 专家坐堂 - Foxtable(狐表) - 新一代数据库软件，完美融合Access、Foxpro、Excel、vb.net之优势，人人都能掌握的快速软件开发工具!

下面的方法报了这么一个错误。是哪里出错了?

System.Data.SqlClient.SqlException: 数据类型 ntext 和 varchar 在 equal to 运算符中不兼容。

Public Function GetState1Refine(ByVal ddh As String, ByVal ddhh As String, ByVal wlbm As String, ByVal lhbbh As String, ByVal rjbb As String) As String
        Dim cnStr As String = "Data Source=172.16.11.201;Initial Catalog=songjiang;Integrated Security=False;User ID=sa;Password=bdcom103liujy;"
        Dim cn As New SqlClient.SqlConnection(cnStr)
        cn.Open()
        Dim filter As String = "1=1"
        If ddh = "null" Then
            filter &= " and 订单号 is null"
        ElseIf ddh > "" Then
            filter &= " and 订单号 = '" & ddh & "'"
        End If

       If ddhh = "null" Then
            filter &= " and 订单行号 is null"
        ElseIf ddhh > "" Then
            filter &= " and 订单行号 = '" & ddhh & "'"
        End If

        
        If wlbm = "null" Then
            filter &= " and 物料编码 is null"
        ElseIf wlbm > "" Then
            filter &= " and 物料编码 = '" & wlbm & "'"
        End If

        If lhbbh = "null" Then
            filter &= " and 两化表编号 is NULL"
        ElseIf lhbbh > "" Then
            filter &= " and 两化表编号 like '%" & lhbbh & "%'"
        End If
        
        If rjbb = "null" Then
            filter &= " and 软件版本 is null"
        ElseIf rjbb > "" Then
            filter &= " and 软件版本 = '" & rjbb & "'"
        End If

        Dim adapter As New SqlClient.SqlDataAdapter("sele ct * from [可用数量表] where " & filter, cn)

        Dim dt As New DataTable
        adapter.Fill(dt)
        cn.Close()

做类型转换

Convert(varchar, 备注类型的列名) = 'xxx'

在那里改呢?改哪一句?

Public Shared Function ConvertToJsonObject(ByVal dataTable As DataTable) As String

Dim result As New Dictionary(Of String, WarecodeStateJsonModel)

For Each dr As DataRow In dataTable.Rows

Dim wareCode As String

wareCode = dr("库位类别").ToString()

If (result.ContainsKey(wareCode)) Then

Dim model = result(wareCode)

model.rootWorks.Add(GetWareRootWork(dr))

Else

Dim model As New WarecodeStateJsonModel

model.wareCode = wareCode

model.rootWorks.Add(GetWareRootWork(dr))

result.Add(wareCode, model)

End If

Dim models As New List(Of WarecodeStateJsonModel)

For Each warecodeStateJsonModel As WarecodeStateJsonModel In result.Values

models.Add(warecodeStateJsonModel)

Return JsonConvertor.ObjectToJson(models)

End Function

Public Shared Function GetWareRootWork(ByVal dr1 As DataRow) As WareRootWork

Dim rootWork As New WareRootWork(dr1("_Identify").ToString(), dr1("生产订单号码").ToString(), dr1("工单行号").ToString(), dr1("订单号").ToString(), dr1("订单行号").ToString(), dr1("物料编码").ToString(), dr1("软件版本").ToString(), dr1("两化表编号").ToString(), dr1("数量").ToString(), Format(dr1("入库时间"), "yyyy-MM-dd HH:mm:ss"))

Return rootWork

End Function

比如

filter &= " and 软件版本 = '" & rjbb & "'"

改成

filter &= " and Convert(varchar, 软件版本) = '" & rjbb & "'"

主题：数据类型 ntext 和 varchar 在 equal to 运算符中不兼容。