ACC2000: Four Ways to Move to a Record from a Combo Box Selection (209537)

MORE INFORMATION

Microsoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements. CAUTION: If you follow the steps in this example, you modify the sample database Northwind.mdb. You may want to back up the Northwind.mdb file and follow these steps on a copy of the database.

The following table compares the features (benefits and drawbacks) of the four methods:

   Method Number:                  1   2   3   4
   ---------------------------------------------
   Requires no code/macros                 x   x
   Saves on subforms               x   x       x
   Can scroll to other records     x       x   x
   Does not require a query        x   x   x
   Can edit records                x   x   x

NOTE: These methods can also apply to text boxes.

Method 1

Create a form called frmComboTest based on the Products table, and set the form's DefaultView property to Single Form.
Add an unbound combo box by using the Control Wizard. (To use the Control Wizard, make sure that the Control Wizards button is pressed in on the toolbox before you create the combo box.) In the Control Wizard dialog box, follow these steps:
1. Click the Find a record on my form based on the value I selected in my combo box button, and then click Next.
2. Include the ProductID and ProductName fields, and then click Next.
3. Click Finish.
The Control Wizard creates an event procedure similar to the following:
```
Sub ComboNN_AfterUpdate()
   'Find the record that matches the control.
   Me.RecordsetClone.Findfirst "[ProductID] = " & Me![ComboNN]
   Me.Bookmark = Me.RecordSetClone.Bookmark
End Sub
					
```
View the frmComboTest form in Form view. Note that when you choose a product name in the combo box, you are moved to the record selected.

Method 2

Create a form called frmComboTest based on the Products table, and set the form's DefaultView property to Single Form.
Set the Filter property for the frmComboTest form to the following:
[ProductName] = Forms![frmComboTest]![cboLookup]

Add an unbound combo box called cboLookup, and set the control's properties as follows. The combo box can be located anywhere on the form, but preferably in the form header or footer.

   Combo Box
   ----------------------------------------------
   ControlName: cboLookup
   ControlSource: <leave blank>
   RowSourceType: Table/Query
   RowSource: Select [ProductName] from Products;
   BoundColumn: 1
   ColumnWidths: 1"
   AfterUpdate: mcrLocateProduct

Create the following macro called mcrLocateProduct:

   Macro Name          Action
   ----------------------------
   mcrLocateProduct    SetValue
                       Requery

   mcrLocateProduct Actions
   --------------------------------------
   SetValue
   Item: Forms![frmComboTest].FilterOn
   Expression: True

When you open frmComboTest and select a product name from the cboLookup combo box, the filter is set to that value.

Method 3

Create a new form not based on any table or query. Add a combo box, and set the control's properties as follows:

   Combo Box
   ----------------------------
   ControlName: cboLookup
   ControlSource: <leave blank>
   RowSourceType: Table/Query
   RowSource: Products
   ColumnCount: 4
   ColumnWidths: 0";2"
   BoundColumn: 1

Create a second form based on the Products table to use as a subform, and set the form's DefaultView property to Single Form.
Add the following text box to the form:
```
   Text Box
   ------------------------
   ControlName: ProductID
   ControlSource: ProductID
   Visible: Yes
						
```
NOTE: Include at least the ProductID field on the new form. However, additional fields may help to illustrate that you have changed records based on the value selected in the combo box.
Save the form, and then use it to create a subform control on the first form by dragging it from the Database window to the detail section of the first form.

Set the subform control properties as follows:

   Subform
   ----------------------------
   LinkChildFields: [ProductID]
   LinkMasterFields: cboLookup

By changing the value in cboLookup, Access ensures that the records in the subform match the combo box.

The Orders form in Northwind.mdb illustrates this method. The Order Details subform is related by the LinkMasterFields and LinkChildFields properties.

Method 4

Create a table called tblProductSelect that has a single field, ProductID. Set the field's Data Type to Number and the Field Size to Long Integer. A primary key is not necessary. Also, you should add no records to this table.

Create the following query called qryProductSelect, based on a join between the ProductID fields of the tblProductSelect and Products tables. Include the following attributes in the query:

   Query: qryProductSelect
   -----------------------------------------------
   Field: ProductID
   Table Name: tblProductSelect
   Show: X (checked on)

   Field: <any other fields you are interested in>
   TableName: Products

Create a form based on qryProductSelect, and add all fields. You must add at least the ProductID field.

Delete the text box control for ProductID and re-create it as a combo box, as follows:

   Combo Box
   --------------------------
   ControlName: ProductID
   ControlSource: ProductID
   RowSourceType: Table/Query
   RowSource: Products
   ColumnCount: 1
   ColumnWidths: 2"
   BoundColumn: 1