The Enter Data Update Rules option on the Update Builder menu brings up the Data Update Rules form, where you define how tables and fields are to be updated.
How to Update Tables
On this form, you can define how entire tables are updated as well as individual fields of specific records. If a record is not created for a table on this form and therefore a Table Update method is not selected, the update version of the table simply replaces the userís version of the table. For table updates, the update version of the table is always updated by the selected Table Update method as described below before the userís version of the table is replaced with the updated version. In this way, any structural changes to a table, because that change is reflected in the update version of the table, will be reflected in the userís version when it is replaced. The Table Update methods are:
∑ Maintain user data: Only records in the userís version of the table are retained. Any records in the update version of the table are zapped.
∑ Replace user data with update data: Only records in the update version of the table are retained.
∑ Combine user data and update data: The records in the userís version of the table are combined with the records in the update version of the table. If there are records in each of the two tables that have the same PK value, the duplicate record from the userís version of the table is retained and the record from the update version of the table is discarded.
∑ Delete table: Delete the table.
How to Update Fields
The Field Updates area of the form allows you to specify how fields within specific records are updated. Once the table level update has been performed, the Field Updates are applied. The field to be updated is identified by selecting a field in the Field combo box and filling in the PK field value(s) in the text box(es) that appear below the grid. If the field to be updated is in a single-record table, the PK field(s), if any, do not need to be filled-in. The Field Update methods are:
∑ Table (T): If the check box in the column with the ďTĒ heading is checked, the value to be placed in the field will come from the record in the update table that has the same PK.
∑ Value: The value to be placed in the field will come from the value entered into the Value field.