主题：关于随机抽取记录问题

假如在题库中抽取100个记录，其中50个是单选题，50个是多选，我想实现抽取20个单选，10个多选，如在单选题中抽取时遇到有2个问的题时，总抽选题数就少1个，保持问题总数为20个，如何实现，请各位专家老师，指点一下，谢谢

Dim cnt As Integer = DataTables("题库").DataRows.Count
Dim ids1 As New List(of Integer)
Dim ids2 As New List(of Integer)
For i As Integer = 0 To cnt -1
    ids1.add(i)
Next
For i As Integer = 0 To cnt - 1
    ids2.Add(ids1(rand.Next(0,ids1.count)))
Next
Tables("题库").StopRedraw()
DataTables("题库").ReplaceFor("选择",False)
For i As Integer = 0 To args(0) -1 '100为要抽取的行数
    DataTables("题库").DataRows(ids2(i))("选择") = True
    If Functions.Execute("Q_Number",DataTables("题库").DataRows(ids2(i))("题目内容"),"（？）" ) > 1 Then
     i += 1
    msgbox(i)
    End If   
Next
Tables("题库").Filter = "[选择] = True"
Tables("题库").ResumeRedraw()

我之前听取了你的建议，更改了表结构，原来是把有两个问的拆成两行，抽取时连续两条记录且顺序不能变你说有缺陷我调整了表结构。现在调整后有两个问题的还是保持一行记录，只是要在抽取的时候判断一下抽取的记录是否存在有两个问题，如有两个问我的就少抽取一行。这样也不能实现吗？

谢谢我实现了，我在选题时，来调整总结数量

'''
Dim cnt As Integer = DataTables("题库").DataRows.Count
Dim ids1 As New List(of Integer)
Dim ids2 As New List(of Integer)
For i As Integer = 0 To cnt -1
    ids1.add(i)
Next
For i As Integer = 0 To cnt - 1
    ids2.Add(ids1(rand.Next(0,ids1.count)))
Next
Tables("题库").StopRedraw()
'DataTables("题库").ReplaceFor("选择",False)
DataTables("题库").ReplaceFor("选题",False)
DataTables("题库").ReplaceFor("选择","")
Dim c As  Integer = 10
For i As Integer = 0 To c -1 '100为要抽取的行数
    DataTables("题库").DataRows(ids2(i))("选题") = True
    If Functions.Execute("Q_Number",DataTables("题库").DataRows(ids2(i))("题目内容"),"（？）" ) > 1 Then
     c -= 1
    'msgbox(i)
    End If   
Next
Tables("题库").Filter = "[选题] = True"
Tables("题库").ResumeRedraw()