About controlling updates

When InfoMaker generates the basic form, it defines whether the data is updatable by default as follows:

  • If the form contains columns from a single table and includes that table's key columns, InfoMaker defines all columns as updatable and specifies a nonzero tab order for each column, allowing users to tab to the columns.

  • If the form contains columns from two or more tables or from a view, InfoMaker defines all columns as not being updatable and sets all tab orders to zero, preventing users from tabbing to them.

You can accept the default settings or modify the update characteristics for a form.

Data sources in the master/detail styles

The master/detail styles have a data source for the master area and a data source for the detail area. Each of the data sources can be updatable.

What you can do

You can:

  • Allow updates in a form associated with multiple tables or a view; you can define one of the tables as being updatable

  • Prevent updates in a form associated with one table

  • Prevent updates to specific columns in a form that is associated with an updatable table

  • Specify which columns uniquely identify a row to be updated

  • Specify which columns will be included in the WHERE clause of the UPDATE or DELETE statement InfoMaker generates to update the database

  • Specify whether InfoMaker generates an UPDATE statement, or a DELETE then an INSERT statement, to update the database when users modify the values in a key column

Updatability of views

Some views are logically updatable; some are not. For the rules your DBMS follows for updating views, see your DBMS documentation.

To specify update characteristics for a form:

  1. Select Design>Update Properties from the menu bar.

  2. If the form is a master/detail style, select the data source as prompted.

    The Specify Update Properties dialog box displays.

  3. To prevent updates to the data, make sure the Allow Updates box is not selected.

    To allow updates, select the Allow Updates box and specify the other settings as described below.

  4. Click OK.

Changing tab values

InfoMaker does not change the tab values associated with columns after you change the update characteristics of the form. If you have allowed updates to a table in a multitable form, you should change the tab values for the updatable columns so that users can tab to them.

For more information, see Defining the tab order in a form.