A virtual column is an IDE virtual object that contains values calculated using the data of other columns. It is not defined in the database code, and it cannot be used to create indexes. The data of the virtual column is not stored in the database.
For example, to have a column that would contain data from both
last_name columns, create a virtual column with the following expression:
first_name || '.' || last_name.
The virtual column with your expression result will appear in the table, and it will also be available in the Database tool window as a virtual object.
The expression used to calculate values for virtual column is stored in external-data-<data_source_name>.xml. You can select another name for the XML file and other place to store this file. To change or see the path to the XML document, open data source settings by pressing Shift+Enter, click the Options tab and see the Virtual objects and attributes field.
For the table column icons, refer to Possible icon combinations for columns.
Create a virtual column
In the Database tool window ( ) , expand the data source tree until the nodes of tables.
Right-click the table node and select.
In the Modify dialog that opens, enter the name of your virtual column in the Name field.
Type your expression in the Expression field.
If the Save external data for <data_source_name> dialog opens, specify the directory for external-data-<data_source_name>.xml file and click Save.