【发布时间】：2012-11-12 13:44:54
【问题描述】：
在 Access 2010 中，我有表 Task 和 Action，它们通过表 ActionTask 具有多对多关系。在Task 的表单中，我想通过ActionTask 联结表为所有与当前任务相关的Actions 放置一个子表单。
这本身，我可以做到。
诀窍在于Action 实际上是四层表的最底层。
每个Action属于一个Goal，每个Goal属于一个Theme，每个Theme属于一个Strategy。
我想为Strategy/Theme/Goal/Action 使用级联组合框，而不仅仅是列出所有可用的Actions 的组合框。
这个我也可以。
问题是当我在数据表中使用此技术时，如果我选择给定行，则所选行显示正确的Strategy/Theme/Goal/Action，但在所有其他行中
-
Action为空白 -
Strategy/Theme/Goal设置为当前行的值，而不是该行的值
我尝试使用“连续表单”视图而不是“数据表”视图，但结果几乎相同。
我想我知道为什么（我的Form_Current 回调中的Me.StrategyCombo = ... 内容），但我不知道另一种实现方式。
如何让子表单正确显示所有行？
Here's the Access file，但所有相关细节都应该在下面。
Tables:
Strategy : (ID, Desc)
Theme : (ID, StrategyID, Desc)
Goal : (ID, ThemeID, Desc)
Action : (ID, GoalID, Desc)
Task : (ID, Desc, ...)
ActionTask : (ActionID, TaskID)
Form Settings:
[Forms]![Task]![ActionTaskSub]:
Link Master Fields: ID
Link Child Fields : TaskID
[Forms]![Task]![ActionTaskSub].[Form]:
On Current:
Private Sub Form_Current()
' when the form loads a record, should reverse propegate
' action > goal > theme > strategy
Dim goalID, themeID, strategyID
' figure out the goal, theme, and strategy that go with this action
If (Me.ActionID) Then
goalID = DLookup("[GoalID]", "Action", "[ID] = " & CStr(Me.ActionID))
themeID = DLookup("[ThemeID]", "Goal", "[ID] = " & CStr(goalID))
strategyID = DLookup("[StrategyID]", "Theme", "[ID] = " & CStr(themeID))
End if
' populate the combo boxes and make the appropriate selections
Me.StrategyCombo = strategyID
Me.ThemeCombo.Requery
Me.ThemeCombo = themeID
Me.GoalCombo.Requery
Me.GoalCombo = goalID
Me.ActionCombo.Requery
Me.ActionCombo = Me.ActionID
End Sub
[Forms]![Task]![ActionTaskSub].[Form]![StrategyCombo]:
Row Source : SELECT [Strategy].[ID], [Strategy].[Desc] FROM [Strategy];
After Update:
Private Sub StrategyCombo_AfterUpdate()
Me.ThemeCombo = Null
Me.ThemeCombo.Requery
Call ThemeCombo_AfterUpdate
End Sub
[Forms]![Task]![ActionTaskSub].[Form]![ThemeCombo]:
Row Source : SELECT [Theme].[ID], [Theme].[Desc] FROM [Theme] WHERE
[Theme].[StrategyID] = [Forms]![Task]![ActionTaskSub].[Form]![StrategyCombo];
After Update:
Private Sub ThemeCombo_AfterUpdate()
Me.GoalCombo = Null
Me.GoalCombo.Requery
Call GoalCombo_AfterUpdate
End Sub
[Forms]![Task]![ActionTaskSub].[Form]![GoalCombo]:
Row Source : SELECT [Goal].[ID], [Goal].[Desc] FROM [Goal] WHERE
[Goal].[ThemeID] = [Forms]![Task]![ActionTaskSub].[Form]![ThemeCombo];
After Update:
Private Sub GoalCombo_AfterUpdate()
Me.ActionCombo = Null
Me.ActionCombo.Requery
End Sub
[Forms]![Task]![ActionTaskSub].[Form]![ActionCombo]:
Row Source : SELECT [Action].[ID], [Action].[Desc] FROM [Action] WHERE
[Action].[GoalID] = [Forms]![Task]![ActionTaskSub].[Form]![GoalCombo];
【问题讨论】：