Database access implementation class generation

Java™ interfaces are used to define how the entity data is persisted and queried in the database.

When you create a data addition, data extension or query extension, various Java interfaces with the suffix Data are generated in the entityObject Java package. These interfaces define how the entity data is persisted and queried in the database.

Note: For more information about this topic, see Customizing physical MDM capabilities.

To generate the implementation, the following information is required for each method in the interface:

SQL statement
Parameter metadata
Result set metadata

The parameter and result set metadata can be specified in the Java interfaces using annotations, or the code generator can acquire the metadata by connecting to a database where the associated tables are available.

For data additions, all the required metadata is added to the Java interfaces during the generation process, and you do not need to modify it unless you are also customizing the SQL.

For query extensions and data extensions that override the base queries, the metadata cannot be generated and you must modify the generated SQL to provide the required metadata. As a result, the first time you generate code for a query extension or a data extension which overrides base queries, the code generation fails with an error because the required metadata is not yet available. You will see the following error message:

Generated files must be customized before code generation can be completed.  
Please see the high priority tasks in the Tasks view.

You must modify the generated InquiryData classes then run code generation again to generate all the required code. Alternatively, you can modify mdmgen.properties to acquire the necessary metadata from the database instead.

Last updated: 23 October 2014