Rational Data Architect and DB2 9: The Database Explorer - Page 3

Working with database connections from the Database Explorer view

Before you can perform any actions on a database, you need to connect to it. A database connection in this view will have a green icon () beside it. When you don’t have a connection to a database, its corresponding icon will be grey ().

Working with disconnected databases

When you don’t have a connection to a database, you can still perform a number of functions on the database connection object (though not on the database itself). Highlight the connection object, right-click, and select one of the following options:

• Delete – Removes a database connection from the Database Explorer view. (This action doesn’t drop the database, just the connection from Rational DA.)
• New SQL Statement - Creates a new SQL statement to run against the target database. This action will automatically attempt a connection to the selected database and start the New SQL Statement wizard (covered later in this series).
• Refresh – Updates the view in the Database Explorer after, for example, a database was dropped or you changed the filter settings for a database connection.
• Edit Connection - Opens the New Connection wizard where you can change the configuration settings of an existing database connection.
• Work Offline - Enables you to work with the database schema offline. This gives you the ability to get assistance for generating SQL statements, visualizing schemas, and more, without having to have a live connection to the database. In order to use this option, you have to enable the database connection for offline work during a connected database session (detailed later in this article).
• Reconnect – Attempts to reconnect to a database. On each attempt, you will be prompted for a valid user ID and password:

Working with connected databases

When you have a connection to a database, you can perform some additional functions on the database connection object, as well as work with objects within the database itself. (Unlike disconnected connections, you can expand a connected connection object to show the actual database and its contents.)

Instead of the Reconnect option, of course, you have the Disconnect option when working with a live database connection. You can also select the Save Offline option to enable the Work Offline option described in the “Working with disconnected databases” section. This option instructs Rational DA to save a copy of the database schema for use when a database connection is not present. The process to create an offline copy of the database schema can take a long time depending on the size of your database. To have this work performed in the background, click Run in Background.

After you have created an offline work environment, the next time you select the Work Offline option for a disconnected database connection object, you can use the objects within it from the cache, as shown below:

You can see in the previous figure that even though the SAMPLE database doesn’t have a live connection, this object has a sub-tree that contains the actual database and enabled folders so that you can perform actions on its objects. Note that this only provides you access to the schema for design purposes. For example, you couldn’t run an SQL statement from a disconnected database in offline mode, but you could create one.

Wrapping it all up

In this article, I showed you how to add and work with database connection objects in the Rational Data Architect Database Explorer view. In the next two articles, I will focus on solving real business problems with Rational DA, and show you more functions that you can perform. In the next article, I take you on a tour of all operations you can perform against the database objects of a connected database.

» See All Articles by Columnist Paul C. Zikopoulos

About the Author

Paul C. Zikopoulos, BA, MBA, is an award-winning writer and speaker with the IBM Database Competitive Technology team. He has more than ten years of experience with DB2 and has written more than one hundred magazine articles and currently working on his tenth book. Paul has co-authoed the books DB2 9: New Features, Information on Demand: Introduction DB2 9 New Features, Off to the Races with Apache Derby, DB2 Version 8: The Official Guide, DB2: The Complete Reference, DB2 Fundamentals Certification for Dummies, DB2 for Dummies, and A DBA's Guide to Databases on Linux. Paul is a DB2 Certified Advanced Technical Expert (DRDA and Cluster/EEE) and a DB2 Certified Solutions Expert (Business Intelligence and Database Administration). In his spare time, he enjoys all sorts of sporting activities, running with his dog Chachi, and trying to figure out the world according to Chloë – his new daughter. You can reach him at: mailto:paulz_ibm@msn.com.

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Disclaimer

The opinions, solutions, and advice in this article are from the author’s experiences and are not intended to represent official communication from IBM or an endorsement of any products listed within. Neither the author nor IBM is liable for any of the contents in this article. The accuracy of the information in this article is based on the author’s knowledge at the time of writing.