To preview a Query Object within the IDE, make sure the database connection is configured and there is no pending reorganization. In addition, keep in mind the following considerations:
- Dameng displays sample data instead of the data from your database.
- If you are using Oracle, DB2 iSeries or SAP HANA, you must copy certain dependencies to the preview folder. Otherwise, the output window may display a message indicating which files must be copied and where to copy them.
- Query Preview in Java environments: In Java environments, Query Preview does not use the generated Java application. Instead, it runs as a .NET–based tool and connects to the database using ADO.NET. For this reason, ADO.NET connection settings must be configured, even if the application itself uses JDBC. For more information, see Access technology to set property.
By default, the Query Object supports querying a single database referenced by the default data stores. If you use multiple data stores to connect to different database engines, you cannot reference attributes from different data stores in a single query definition. There is a special case that is supported when multiple data stores reference the same database engine instance.