Schema map

The schema map feature allows you to view the relations between tables in a visual manner and explore the structure of the tables.

To view the Schema map for the incident table, in the Tables & Columns module, select the Incident table in the Tables names list and click on the Schema map button:

When in the Schema map page, we can quickly jump from one table to another using the document reference field available in the top-left corner, as shown in the following screenshot:

As shown previously, we can also use the check-box filters to show or hide interrelated tables based on their relationship type. The following filters based on relationship types are available to us:

• Show referenced tables: If checked, this displays all tables whose records are referenced from the current table
• Show referencing tables: If checked, this displays all tables that have a field that refers to the record of the current table
• Show extended tables: If checked, this displays the table (parent class) from which the current table (child class) is extended
• Show extending tables: If checked, this displays all tables (child classes) that are extending the current table (parent class)

In the schema map, we can click on the + icon next to the label Columns in order to see all the fields in the selected table:

To view the columns of the extended table (the parent class), click the + icon next to the extended table's name, shown in green in the following screenshot:

We can also click on any of the field's titles to open its dictionary definition (more on Dictionary later in the chapter). Clicking on the reference field links (in red) will take you to the schema map of the referenced table. For example, if you click on the reference to the Configuration item link, as shown in the preceding screenshot, you will be taken to the schema map of the Configuration item (cmdb_ci) table.