Managing Database Queries

Editing Database Queries

You do not have to select a node to edit database queries using this dialog box. You can create new expressions or delete and edit existing expressions.

To select a database query

1. Select Edit database query in the Edit menu.
2. Mark a database query list on the left-hand side of the Edit database queries dialog box.
3. Perform one of the following tasks.
   1. Overwrite the database expression name in the Identifier.
   2. Enter explanatory text in Description.
   3. Edit the SQL expression.
   4. Select or deselect other dialog groups.
   5. Select all dialog groups or deselect them all.
   6. Test the expression by clicking on Test statement... and enter a parameter value in the next dialog box.
4. Save the changes.

Loading a Historical Object State

You can reset the state of a database object in a collection if you have enable recording of historical data in the database.

To reset a database object to a previous state

1. Enter a database collection.

   For more information, see "Database Objects" as a collection.

2. Add the action Load objects including history to an action node.
3. Select the collection on this node.
4. Select between two variations:
   1. Select Load a single object with its history to load the historical data for a single object.

      Here, you can enter an object key (XObjectKey), which uniquely identifies the object.

   2. Select Load table with history to load the historical table data.

      You can enter a column name and its value as limiting criterion here.

5. Add the action Set object to historical state on the action node.
6. Select the collection.
7. Enter the date under Date.

   The collection is set to the state, which was current at that time.

Loading a Change History

A change history contain a list of all operations recorded on a defined amount of data. You can load a change history into a special collection type designed for the purpose.

To define a collection for a change history

1. Open the module or component to which to add the collection.
2. Select the Collections node with a right click.
3. Select Change history.
4. Enter the name for the new collection in Identifier.
5. Select the type of change history in Type.

To load a change history

1. Select an action node with a right click.
2. Select Load change history.
3. Select the collection you want under Collection.
4. Select the type of change history defined on the collection in Type.

   NOTE: The setting in Type must be identical for the collection and the change history to be loaded.

5. Enter the date up to which you want to load the change history in Load historical data back to (date).
6. Select one of the following variations to continue:
   1. Enter the Web SQL expression for the (XObjectKey) object key of the relevant object. This loads the change history for an individual object.
   2. Enter the relevant table name to load the change history for a table or an assignment object.

   Note: If you wish, you can also enter the column name and value for a filter condition.

   Tip: Column-dependent references are recommended for displaying historical data. For more information, see Column-dependent references.

View Definitions

A collection layer view behaves in the same way as a database layer view. The content of the view is defined via a Web SQL expression. The view is updated during runtime. The view is automatically updated if the source data changes.

To add a view

1. Select the Collections node with a right click.
2. Select the action Add collection data view.
3. Enter the name for the new collection in the Identifier text field.
4. Enter the Web SQL expression for representing the view content in the View expression field.