Connect to and Query DB2 Data in QlikView over ODBC

The CData ODBC drivers expand your ability to work with data from hundreds of data sources. QlikView is a business discovery platform that provides self-service BI for all business users in an organization. This article outlines simple steps to connect to DB2 data using the CData ODBC driver and create data visualizations in QlikView.

The CData ODBC drivers offer unmatched performance for interacting with live DB2 data in QlikView due to optimized data processing built into the driver. When you issue complex SQL queries from QlikView to DB2, the driver pushes supported SQL operations, like filters and aggregations, directly to DB2 and utilizes the embedded SQL engine to process unsupported operations (often SQL functions and JOIN operations) client-side. With built-in dynamic metadata querying, you can visualize and analyze DB2 data using native QlikView data types.

Connect to DB2 as an ODBC Data Source

If you have not already, first specify connection properties in an ODBC DSN (data source name). This is the last step of the driver installation. You can use the Microsoft ODBC Data Source Administrator to create and configure ODBC DSNs.

Set the following properties to connect to DB2:

• Server: Set this to the name of the server running DB2.
• Port: Set this to the port the DB2 server is listening on.
• Database: Set this to the name of the DB2 database.
• User: Set this to the username of a user allowed to access the database.
• Password: Set this to the password of a user allowed to access the database.

You will also need to install the corresponding DB2 driver:

• Windows: Install the IBM Data Server Provider for .NET.

  On Windows, installing the IBM Data Server Provider is sufficient, as the installation registers it in the machine.config.

• Java: Install the IBM Data Server Driver for JDBC.

  In the Java version, place the IBM Data Server Driver JAR in the www\WEB-INF\lib\ folder for this application.

When you configure the DSN, you may also want to set the Max Rows connection property. This will limit the number of rows returned, which is especially helpful for improving performance when designing reports and visualizations.

Populate a Chart with DB2 Data

The steps below supply the results of an SQL query to a visualization in QlikView. In this article, you will create a bar chart with the query below:

SELECT Orders.Freight, Customers.ContactName FROM Customers INNER JOIN Orders ON Customers.CustomerId=Orders.CustomerId

1. Click File -> Edit Script (or click the Edit Script button in the Toolbar).
2. On the Data tab, select ODBC in the Database menu and click Connect. 👁 Connecting to an ODBC data source.
   
3. Select the DSN (CData DB2 Sys) in the resulting dialog. 👁 Selecting a DSN (Salesforce is shown).
   A command like the following is generated:

   ODBC CONNECT TO [CData DB2 Sys];
   

4. Enter the SQL query directly into the script with the SQL command (or click Select to build the query in the SELECT statement wizard).

   SQL SELECT Orders.Freight, Customers.ContactName FROM Customers INNER JOIN Orders ON Customers.CustomerId=Orders.CustomerId;
   

   Where possible, the SQL operations in the query, like filters and aggregations, will be pushed down to DB2, while any unsupported operations (which can include SQL functions and JOIN operations) will be managed client-side by the CData SQL engine embedded in the driver.

   👁 A script that connects and executes an SQL query. (Salesforce is shown.)
   
5. Close the script editor and reload the document to execute the script.
6. Click Tools -> Quick Chart Wizard. In the wizard, select the chart type. This example uses a bar chart. When building the chart, you have access to the fields from DB2, typed appropriately for QlikView, thanks to built-in dynamic metadata querying.
7. When defining Dimensions, select OrderName in the First Dimension menu.
8. When defining Expressions, click the summary function you want and select Freight in the menu.

9. Finish the wizard to generate the chart. The CData ODBC Driver for DB2 connects to live DB2 data, so the chart can be refreshed to see real-time changes. Live connections are possible and effective, thanks to the high-performance data processing native to CData ODBC Drivers.

   👁 A chart populated with the results of a query. (Salesforce is shown.)