Schema Map for Tables
The schema map displays the details of tables and their relationships in a visual manner, allowing administrators to view and easily access different parts of the database schema. The schema map can also be printed directly from a browser.
|Note: The schema map is significantly enhanced as of the Calgary release. If you are using an older version, see previous version information.|
Schema relationship types supported, and the colors used for them, are:
|Relationship type||Color used|
By default, all these types of relationship are displayed, but you can view or hide each type.
The following enhancements have been added as of the Calgary release:
- Relationship types are displayed.
- Relationship views can be customized.
- The color scheme relates to relationship types.
- You can drill down through the table hierarchy.
- Selected tables can be hidden from view.
- The schema map can be printed from the browser.
3 Generating a Schema Map
To generate a schema map:
- Navigate to System Definition > Tables & Columns.
- In the Table Names pane, select a table.
- Click Schema map.
- The schema map for the selected table opens in a separate tab or window.
You can print this map from the browser, if required.
4 Viewing the Schema Map
The schema map shows the selected table in yellow, typically centered, and all tables related to that table, typically shown at the sides.
From this map:
- The check boxes at the top allow you to control which relationships to display. Select or clear a relationship type to display or hide tables with that relationship to the selected table.
- Each related table has a colored bar indicating the relationship to the selected table.
- You can point to the connector lines to display the details of a relationship between the two tables.
|Note: Since relationships are shown as single lines for simplicity, the diagrams rendered are not entity relationship diagrams.|
4.1 Using the Table Selector
To view a schema map as a list, point to the table selector in the right corner:
- Click a table in the list to scroll the schema map to that table.
- Click the eye icon beside a listed table to hide or show that table in the schema map.
- Click the pin icon in the selector to keep the list open.
4.2 Using Related Tables
Right-click a table node header to display a context menu with these functions:
- Focus on this table: make the selected table the new focus table and redraw the schema map based on the new selection.
- The new focus table is added as a breadcrumb at the top, allowing you to return to the previous table at any time.
- Go to list: display the list of records for the table.
- Go to dictionary: display the system dictionary, filtered for the selected table.
To hide a related table from view, click the eye icon in the node header (the node can be made visible again with the table selector).
For tables that are part of their own inheritance hierarchy, click the expand button (+) in the node header to add their inheritance hierarchy to the schema map.
4.3 Viewing More Information
Click the expand button (+) beside Columns to expand the table fields.
The reference fields show a red notation of the table they refer to.
If any tables extend from a table, their columns are displayed in reverse inheritance order. For example:
Here, the Server [cmdb_ci_server] table extends from Computer [cmdb_ci_computer], Hardware [cmdb_ci_hardware], and Configuration Item [cmdb_ci], and displays the columns from those tables.
Similarly, the Computer table displays the columns from the Hardware and Configuration Item tables.
5 Versions Prior to the Calgary Release
|Click the plus to expand previous version information|
5.1 Legacy Schema Map for Tables
The Schema Map provides a graphical representation of the relationships between tables, either through class extension or reference. To view the schema map for a table:
To help visually identify extensions, each color represents another level of class extension:
The following image shows an example schema map for the Computer [cmdb_ci_computer] table. In the example, all the tables that extend cmdb_ci_computer directly are the same color. Also, all tables that extend cmdb_ci_server (which itself extends cmdb_ci_computer) appear in another color and are on their own arc.
Each deeper level of nesting within the class hierarchy has its own color and appears on an arc further from the center. In the example, everything brown is one level deep. Orange two levels deep. Blue three levels deep. Anything with a color is an extension of something rather than being related via a reference field.