How To Create Data Page In Pega

In this quick tutorial you will learn How To Database Updates in Pega 8.

Databases:

• Most Pega applications need to exchange data with each other as well as with external systems.

PegaRULES database:

• It contains all of the rules and system information for a Pega application.
• Designers can create and update rules and system settings without updating the database structure.
• Detailed knowledge about the database is unnecessary for most application tasks.

PegaDATA database:

• Pega application information such as cases, assignments, and case history is stored in PegaDATA.
• As users interact with a Pega system, rows of the database are automatically created, updated, saved, and deleted.
• Pega separates this data into a separate database from rules and system data to support high availability and in-place upgrades.

External database:

• Pega applications almost always require access to data stored outside of the application.
• To directly manage the data read from and written to an external database, you can create an external class in your application.

External Classes:

• An external class cannot belong to a class group.
• It corresponds to a database table not administered by Pega.
• Each external class should be mapped to a unique database table.
• An external class does not contain either the pzInsKey or pxObjClass properties.
• These properties are used by Pega as key columns to identify rows in tables in the PegaRULES and PegaDATA databases.
• The external class uses the key column specified by the database table to identify unique rows instead.
• An external class maps Pega properties to database columns.

Data Pages:

• As a best practices pega suggest the use of data pages to both read and save data back to the system of record for easy configuration and maintainability.
• By configuring a savable data page, you can read and write updated information without the use of an activity.

Reading and Writing to a Database:

• When advanced processing to a database table cannot be achieved with savable data pages.
• You can read from, and write to the database with Obj-methods using activities.
• Obj-methods are a subset of activity methods used to operate on one or more objects, or rows, in a database table.

Read from a database:

• Obj-Open or Obj-Open-By-Handle loads an instance of a class stored in either the PegaRULES database or an External database.
• Both methods create a clipboard page for the open instance.
• Obj-Browse searches the database, retrieves multiple records, and copies them to the clipboard as an array of embedded pages.
• Obj-Refresh-and-Lock tests whether a clipboard page is current and if a lock is held.
• If the object is not locked, the activity acquires a lock and refreshes the page if it is stale.

Save to a database:

• Obj-Save saves the contents of a clipboard page to the database.
  • It immediately writes the object to the database only if the WriteNow parameter is selected.
  • If the WriteNow parameter is not selected, the Obj-Save operation becomes a deferred save.
  • A deferred save adds a deferred operation to an internal list of operations to be performed on the next commit.
• A valid reason to perform a WriteNow is the need to immediately reread the instance before issuing a commit.

Delete a database record:

• Use Obj-Delete or Obj-Delete-By-Handle to remove an instance from the database.
  • Obj-Delete to delete a database row identified by a page on the clipboard.
  • Obj-Delete-By-Handle to delete an instance using its unique ID without requiring a page on the clipboard.

Cancel/rollback Operations:

• Obj-Save-Cancel: cancels the most recent uncommitted Obj-Save method so that the instance is not written as part of a later Commit operation.
• Rollback method: cancels or withdraws any previous uncommitted changes to the PegaRULES database (and to external databases accessed from an external class) from the current thread.

SQL Connect rules:

• The Connect SQL rule provides four tabs to enter SQL statements that execute during performance – Open, Delete, Save, Browse.
• Use a Connect SQL rule To execute a SQL command or stored procedure
• Invoke Connect SQL rules from an activity using RDB methods.

Hope you learned How To Database Updates in Pega 8.

How To Create Data Page In Pega

Source: https://pegaks.com/how-to-database-updates-in-pega/

Posted by: garciawhar1968.blogspot.com

Share this post