Showing Differences Between Real Databases and Database Schema
As a basis for target-directed customizations, you can view the differences between the relational database's database schema and the database model's data schema.
Prerequisites
You require
- a relational database with the respective login information or
- a DDL file
and
- a model with at least one database schema that contains physical elements, i.e. tables and views.
Context
You can use the comparison to show the differences between physical elements of the relational database or the DDL file and the elements mapped in the database model. You can use this information to decide which database elements you want to put in your model or which ones you want to update.
Use the Database Import Wizard or DDL Import Wizard to import comparison information from a relational database or a DDL file; here you can select the respective source and the table to be imported from it, as well as selecting the database model's data schema as the comparison target.
Source and target side are compared with each other in the Database Manager editor. The display is switched on or off by activating or deactivating the Database Connection>Actions>Show differences toggle menu item. The DB Manager editor needs to be the focus.
The differences are only shown for real database elements in the left list of the tool window and for their subelements that are shown in the bottom area of the tool window once an element has been selected. Differences are only shown for elements with the check box checked in the list's first column.
If you also want to show the differences for other elements, then you need to select these and call Show differences again.
The differences between the physical elements and those in the database model are shown by the font color and a tool tip. The following displays are possible:
| Color | Tool tip | Description |
|---|---|---|
| Black | The element exists in the target schema; all of its properties and subelements are also consistent. | |
| Green | The element doesn't have a corresponding element in the target schema. | The element only exists in the database or DDL file. |
| Blue | The element differs from its corresponding element in the target schema. | The element already exists in the target schema but has different properties or subelements. |
| Red | The element doesn't exist here but only in the target schema. | The element only exists in the target schema but not in the database or DDL file. This difference is only shown for subelements. |
Comparing a Relational Database with a Modeled Database Schema
How to proceed
-
Select Extras>Import>Relational Database.
The Database Import Wizard appears.
-
To add a new connection in the left-hand list of database connections in the wizard, click on
.Defaults are entered in the Connection tab.
- Enter the login information for database access in the Connection and Advanced tabs.
-
Click on the Advanced import button.
The DB Manager editor is opened.
-
If the target package is not yet preallocated or if you wish to select another schema as target, select this from the drop-down list at the top right in the editor.
All database elements found in the schema are shown in the list on the right-hand side.
- To select a database element you want to show the differences for, activate its check box.
-
To show the differences, select the toggle command Database Connection>Actions>Show differences.
All differences between the selected elements from the DDL file and/or the relational database and the existing database schema in the model determined and visualized in the editor. The differences are shown in the left-hand list of imported elements and in the list of subelements in the bottom area of the editor in a different color and with a tool tip. The Black elements existing in the target schema, the Green elements that do not exist, the Blue elements with different properties and subelements and the deleted Red subelements are shown.
Comparing a DDL File with a Modeled Database Schema
How to proceed
-
Select Extras>Import>DDL File.
The DDL Import Wizard appears.
-
To select a DDL file, click on
.The Open dialog appears.
-
Select the DDL file and confirm with Open.
The DDL file's path is shown.
- Select a database schema as the target package.
-
Click on the Advanced import button.
The DB Manager editor is opened.
-
If the target package is not yet preallocated or if you wish to select another schema as target, select this from the drop-down list at the top right in the editor.
All database elements found in the schema are shown in the list on the right-hand side.
- To select a database element you want to show the differences for, activate its check box.
-
To show the differences, select the toggle command Database Connection>Actions>Show differences.
All differences between the selected elements from the DDL file and/or the relational database and the existing database schema in the model determined and visualized in the editor. The differences are shown in the left-hand list of imported elements and in the list of subelements in the bottom area of the editor in a different color and with a tool tip. The Black elements existing in the target schema, the Green elements that do not exist, the Blue elements with different properties and subelements and the deleted Red subelements are shown.