Data Migration
The MJ runtime library helps with migrating statements in MAPPER "RUN" reports, but what about MAPPER reports containing data? Usefully, another feature of MJ is migration of MAPPER data reports to a database like Oracle.
Here is a graphical overview of MJ's ETL (Extract, Transform and Load) process for converting MAPPER report data to domain entities in a relational database:

As illustrated above, MJ produces multiple artifacts as a result of the translating a MAPPER report to a database table, including:
- SQL DDL that creates the new database table.
- Java persistence class that is an object-oriented representation of the entity data in the MAPPER report.
- Hibernate mapping between the database table and Java persistence class.
- Data lines in the MAPPER report are extracted to a CSV formatted file and loaded into the new database table using Scriptella ETL.
Translation of MAPPER reports into database tables is informed by configuration items based on the Java Spring framework. MJ generates a default, "best guess" configuration which can then be fined-tuned manually.
As alluded to above, once migrated, entity data is managed by the popular Hibernate object relational mapping (ORM) package. CRUD (Create, Read, Update, Delete) operations can be performed on entity data using Hibernate and the generated persistence classes.
The pages in this section expand on the topics above. To navigate the pages, click a topic in the left-hand menu, or follow the links below to the next (or previous) page.