ACC: AutoLookup Query Not Performed with 1-to-1 Relationship

   Table 1                  Table 2
   ----------------------   ----------------------
   Primary Key              Primary Key
   Primary Key              Indexed, No Duplicates
   Indexed, No Duplicates   Primary Key
				

MORE INFORMATION

Consider the following tables:

   Employees     Offices
   ----------   ----------
   EmployeeID    OfficeID
   LastName      AssignedTo
				

To ensure that an employee is not assigned to more than one office, add a unique index to the Offices.[AssignedTo] field. Regardless of whether there is no relationship, a one-to-many relationship, or a one-to-one relationship defined between these tables, Microsoft Access will determine that the relationship is one-to-one when determining whether to perform an AutoLookup query.

Steps to Reproduce Behavior

1. Open the sample database Northwind.mdb (or NWIND.MDB in version 2.0) and create the following new table:
   

          Table:  Offices
          --------------------------
          FieldName: OfficeID
             Data Type: AutoNumber
             Field Size: Long Integer
             New Values: Increment
          FieldName: Building
             Data Type: Text
          FieldName: AssignedTo
             Data Type: Number
             FieldSize: Long Integer
             DefaultValue: <blank>
   						

2. Select the OfficeID field, and then click Primary Key on the Edit menu.
3. View the table in Datasheet view, and then add the following data to the table:
   

          OfficeID   Building   AssignedTo
          ----------------------------------
              1          A
              2          A
              3          B
   						

4. Create a new query based on the Employees and Offices tables.
5. Join the tables on the Employees.[EmployeeID] and Offices.[AssignedTo] fields.
6. Drag all the fields from the Offices field list to the query grid, and then drag the FirstName and LastName fields from the Employees field list to the query grid.
7. Run the query. Type 7 in the AssignedTo field, and then press ENTER. Note that the AutoLookup query fills in the FirstName and LastName fields for the record.
8. Save the query as AssignOffices, and then close it.
9. Open the Offices table in Design view.
10. Set the AssignedTo field's Indexed property to Yes (No Duplicates).
11. Save the table and close it.
12. Run the AssignOffices query. Type 3 in the first blank AssignedTo field and press ENTER. Note that Microsoft Access does not fill in the FirstName and LastName fields.
13. Press SHIFT+F9 to requery. Note that the fields are filled.