In a database, a table or view can change in the following ways:
A column is renamed.
A column’s data type changes.
A column is added to the table or view.
A column is dropped from the table or view.
The IO Design perspective can detect these changes and update the map of the table or view. You can update a single map, or update several maps at once.
Map column name and data type changes are propagated to dependent information objects if the information object column uses the default name. If the name change results in a duplicate information object column name, a suffix is added, for example creditLimit_1. A column name is updated in the following tabs in the graphical information object editor if it does not appear in an expression:
Columns
Column Categories
Joins
Filters
Group By
A column name in an expression, such as SUM (quantityOrdered * priceEach), is not updated. If the information object column name has been modified, changes are not propagated.
A column that is added to a map is also added to dependent information objects as a source column. The column is not added to the information object’s SELECT clause. In other words, the column appears in the upper pane of the graphical information object editor, but it is unchecked.
A column that is dropped from a map is not dropped from dependent information objects by default. You must indicate that the column should be dropped. Because this action cannot be undone, back up the project before proceeding.
How to update maps
1 In Navigator, right-click the folder that contains the maps or any of its parent folders and choose Information Objects➛Update Maps.
2 In Database Changes, select the maps to update, as shown in Figure 2‑30. To select all maps in a folder, select the folder. To have the IO Design perspective automatically detect which maps need updating, choose Auto Detect. The Auto Detect operation may take a few moments. Choose Next.
Figure 2‑30 Selecting maps to update
3 For each map that needs updating, make the necessary changes and choose Next.
4 Review your changes carefully. If they are acceptable, choose Finish.
A column is renamed.