The information in this article applies to:
- Microsoft Access version 2.0
SUMMARY
This article describes how you can create a form that has two list boxes
that imitate the multiple-selection capability reflected in Microsoft
Access Wizards.
This method uses a Yes/No field in the table to indicate which records are
selected. One list box displays the Yes records and the other displays the
No records. To move items from one list box to the other, the Yes/No field
of the selected record is set to the appropriate state and the list boxes
are then requeried to update their respective lists.
Note that the method provided is suitable for single-user environments
only. If this method is used in a multiuser environment, what one user
does may interfere with the actions of another. See the "References"
section later in this article for more information on a multiuser
technique.
MORE INFORMATION
In addition to the two list boxes, the form also contains three command
buttons. By using the command buttons, you can add items to, or delete
items from the list box. You can also double-click an item in a list box to
move it to the other list box. To create the form, follow these steps:
- Open the sample database NWIND.MDB and create the following new table:
Table: Table1
---------------------------------------------------
Field Name: List
Data Type: Text
Field Size: 15
Caption: Items that will be provided in list
Field Name: Selected
Data Type: Text
Field Size: 5
Caption: Indicates if the item has been selected
Table Properties: Table1
------------------------
PrimaryKey: List
- View the Table1 table in Datasheet view. Add five records to the table.
For each record, type any text in the List field (for example, a list
of colors or cities), and then type "YES" (without quotation marks) in
the Selected field.
- Create the following new query based on the Table1 table and save it as
Select Yes:
Query: Select Yes
-------------------------------
Field: List
Show: Yes
Criteria: [selected] = "YES"
- Create another new query based on the Table1 table as follows and save
it as Select No:
Query: Select No
------------------------------
Field: List
Show: Yes
Criteria: [selected] = "NO"
- Create a new blank form and save it as SelectList.
- With the SelectList form open in Design view, click Code on the
View menu, and then type the following line in the form module's
Declarations section:
Option Explicit
- Type the following three functions in the form module:
'=======================================================
' The following function opens the table and changes the
' selected value from YES to NO, and then runs the
' query for the two list boxes so that they will display
' the updated values.
'=======================================================
Function Add ()
Dim MyDB As Database
Dim MyTable As Recordset
Dim y As Control
Set y = Me![Field0]
If IsNull(y) Then
MsgBox "Please select something in the list."
Else
Set MyDB = DBEngine.Workspaces(0).Databases(0)
Set MyTable = MyDB.OpenRecordset("Table1")
MyTable.Index = "PrimaryKey"
MyTable.Seek "=", y
MyTable.Edit
MyTable.[Selected] = "no"
MyTable.Update
MyTable.Close
Me![Field0].Requery
Me![Field2].Requery
End If
End Function
'=======================================================
' The following function opens the table and changes the
' selected value from NO to YES, and then runs the
' query for the two list boxes so that they will display
' the updated values.
'=======================================================
Function Del ()
Dim MyDB As Database
Dim MyTable As Recordset
Dim y As Control
Set y = Me![Field2]
If IsNull(y) Then
MsgBox "Please select something in the list."
Else
Set MyDB = DBEngine.Workspaces(0).Databases(0)
Set MyTable = MyDB.OpenRecordset("Table1")
MyTable.Index = "PrimaryKey"
MyTable.Seek "=", y
MyTable.Edit
MyTable.[Selected] = "yes"
MyTable.Update
MyTable.Close
Me![Field0].Requery
Me![Field2].Requery
End If
End Function
'=======================================================
' The following function sets all values in the Selected
' field to YES, and then runs the query for the two list
' boxes so that they will display the updated values.
'=======================================================
Function Clear ()
Dim MyDB As Database
Dim MyTable As Recordset
Set MyDB = DBEngine.Workspaces(0).Databases(0)
Set MyTable = MyDB.OpenRecordset("Table1")
On Error GoTo erhandle
MyTable.MoveFirst
Do Until MyTable.EOF
MyTable.Edit
MyTable.[Selected] = "yes"
MyTable.Update
MyTable.MoveNext
Loop
MyTable.Close
Me![Field0].Requery
Me![Field2].Requery
erhandle:
Resume Next
End Function
- Save and close the form module. Then, add the following list box and
command button controls to the SelectList form:
List Box:
-----------------------------
Name: Field0
RowSourceType: Table/Query
RowSource: Select Yes
OnDblClick: =Add()
List Box:
-----------------------------
Name: Field2
RowSourceType: Table/Query
RowSource: Select No
OnDblClick: =Del()
Command Button:
--------------------
Name: Button One
Caption: Clear
OnClick: =Clear()
Command Button:
--------------------
Name: Button Two
Caption: Add Item
OnClick: =Add()
Command Button:
-----------------------
Name: Button Three
Caption: Delete Item
OnClick: =Del()
- View the SelectList form in Form view. Note that the first list box,
Field0, displays all the items in Table1 you can select. You can
use the Clear, Add Item, or Delete Item buttons to add or remove
items from the second list box, Field2. You can also double-click
an item in a list box to move it to the other list box.
REFERENCES
For more information about how to select more than one item from the
same list box (using an array), see the following article in the Microsoft
Knowledge Base:
ARTICLE-ID: Q121356
TITLE : ACC2: How to Create a Multiple-Selection list box