用下面代码,不能实现?
Dim cmd As New SQLCommand
cmd.C
Dim dt As DataTable
Dim Cols1() As String = {"产品ID", "产品名称"}
Dim Cols2() As String = {"产品ID", "产品名称"}
cmd.CommandText = "SELECK * From {表A} Where {表A}.[产品ID] = {多张表合并}.[产品ID])"
dt = cmd.ExecuteReader()
For Each dr1 As DataRow In dt.DataRows
Dim dr2 As DataRow = DataTables("多张表合并").AddNew()
For i As Integer = 0 To Cols1.Length - 1
dr2(Cols2(i)) = dr1(Cols1(i))
Next
Next
Dim cmd2 As New SQLCommand
cmd2.C
Dim dt2 As DataTable
Dim Cols3() As String = {"客户ID", "客户ID"}
Dim Cols4() As String = {"客户ID", "客户ID"}
cmd2.CommandText = "SELECK * From {表B} Where {表B}.[客户ID] = {多张表合并}.[客户ID])"
dt2 = cmd2.ExecuteReader()
For Each dr1 As DataRow In dt2.DataRows
Dim dr2 As DataRow = DataTables("多张表合并").AddNew()
For i As Integer = 0 To Cols1.Length - 1
dr2(Cols4(i)) = dr1(Cols3(i))
Next
Next
Dim cmd3 As New SQLCommand
cmd3.C
Dim dt3 As DataTable
Dim Cols5() As String = {"产品ID", "产品名称", "客户ID", "客户名称", "单价", "折扣", "数量", "日期" }
Dim Cols6() As String = {"产品ID", "产品名称", "客户ID", "客户名称", "单价", "折扣", "数量", "日期" }
cmd3.CommandText = "SELECK * From {订单A} Where {订单A}.[产品ID] = {多张表合并}.[产品ID] and {订单A}.[客户ID] = {多张表合并}.[客户ID] "
dt3 = cmd3.ExecuteReader()
For Each dr1 As DataRow In dt3.DataRows
Dim dr2 As DataRow = DataTables("多张表合并").AddNew()
For i As Integer = 0 To Cols1.Length - 1
dr2(Cols6(i)) = dr1(Cols5(i))
Next
Next
'查询器生成的SQL语句:
'SelecK{订单}.产品ID, 产品名称, 单价, 折扣, 数量, 日期, 选中, 开piao情况, {订单}.客户ID, 客户名称 From (({订单} Inner Join {产品} On {产品}.[产品ID] = {订单}.[产品ID]) Inner Join {客户} On {客户}.[客户ID] = {订单}.[客户ID])