ACC2000: Example of Row Fix-Up in the Northwind Orders Form (209672)

SUMMARY

Microsoft Access provides an automatic "row fix-up" feature that uses links between tables to update (fix up) records in queries and forms. You can use this feature to enter a single value, and Microsoft Access automatically looks up and displays other values for that record.

Row fix-up enables you to update forms and queries without using macros or code. This article uses the Orders form in the sample database Northwind.mdb or the sample Microsoft Access project NorthwindCS.adp to demonstrate how to set up and use row fix-up.

NOTE: The row fix-up technique is referred to as AutoLookup in Microsoft Access.

MORE INFORMATION

To see an example of the row fix-up technique, follow these steps:

Open the sample database Northwind.mdb or the sample Access project NorthwindCS.adp.
Open the Orders form in Design view.
Select the RecordSource property on the Orders form's property sheet and click the Build (...) button. Note the following about the RecordSource property of the Orders form:
1. The record source is the Orders Qry query or view.
2. The Join property between Customers and Orders tables is:
```
   One                          Many
   -------------------------------------------------
   CUSTOMERS.[CustomerID] ==>  ORDERS.[CustomerID]
						
```
3. The CustomerID field in the query/view grid comes from the Orders table, which is on the "many" side of the relationship, and not from the Customers table, which is on the "one" side of the relationship. (See point 3b, above.)
Close the RecordSource query or view and click the Bill To combo box. Look at its RowSource property on the property sheet. The row source is an SQL Select statement. Click the Build (...) button and note the following about the RowSource query:
1. The query is based on the Customers table.
2. The query returns two columns: CustomerID and CompanyName.
3. The bound column is CustomerID.
4. The visible column is CompanyName.
Microsoft Access select queries are updatable. This means that when you make a change to a query's recordset, Microsoft Access can update the source tables with your changes.

The Bill To combo box presents you with a list of company names from the visible column of its RowSource query. When you select a company name, the combo box stores the bound column--the CustomerID field from the RowSource query--in the CustomerID field in the Orders table. (See points 4c and 4d, above.) It is important to note that the selection is stored in the many- side table. (See point 3c, above.)

After the combo box updates the CustomerID field in the Orders table (the many-side table), the field is changed so it no longer points to the same record in the Customers table (the one-side table). (See point 5, above.) Note that the Orders table is updated because the query's recordset was changed.

Microsoft Access recognizes that the relationship no longer matches; therefore, it automatically updates the relationship by linking the changed record in the Orders table with the appropriate record in the Customers table.

All the fields in the Orders form that come from the Customers table (the one-side table) are updated to show the values in the record for the newly formed link.

Example

When you make a change to the Bill To combo box, Microsoft Access uses row fix-up to update the following fields on the Orders form:

[Address]
[City]
[Region]
[PostalCode]
[Country]

The following fields on the Orders form are not updated by row fix-up. However, they are updated by the AfterUpdate event attached to the Bill To combo box: