Getting Started jOOQ
Setting up the environment
Add the Dependency to your build.
Java 8, 9, 10 , 11 no module-info
Java 6, 7
Java 9, 10 , 11 with module-info
From 7.0.0 you will need explicitly include the jOOQ dependency in your pom.
If you are using jOOQ commercial edition you will need to exclude the dependency as it’s currently scope compiled - will be corrected in next release.
There are 2 mapping strategies available in jOOQ.
- the generated classes from the db information. You will get a record that will have named getters matching the column names.
- the fetchInto(Class) method that will call the jOOQ mapper or a third party mapper specified in the configuration.
because fetchInto has to go through the Record creation, its use will mainly be when your query does not map to a generated object - i.e. a subset of fields or joins -.
SFM as a RecordMapperProvider
Sfm can be plugged into the fetchInto mapping.
All you need to do is
when instantiating your DSL. You will then be able to use fetchInto with a cost very close to fetching the record - see the performance section - and the flexibility that SFM offers.
map subset of select fields
#SFM as a RecordUnmapperProvider
From 8.2.0 we now have a RecordUnmapper available from the JooqMapperFactory.
In 8.2.0 we also introduced the SelectQueryMapper that can deals with join with minimum of effort. It will uses the jOOQ model to determined which field is a key, and also activate the speculative object mapping removing the need for aliasing. The following will now just work out of the box:
SelectQueryMapper<Author> authorMapper = SelectQueryMapperFactory.newInstance().newMapper(Author.class); List<Author> authors = authorMapper.asList(DSL.using(connection) .select(AUTHOR.ID, AUTHOR.FIRST_NAME, AUTHOR.LAST_NAME, AUTHOR.DATE_OF_BIRTH, BOOK.ID, BOOK.TITLE) .from(AUTHOR).leftJoin(BOOK).on(BOOK.AUTHOR_ID.eq(AUTHOR.ID)) .orderBy(AUTHOR.ID));
no need for key definitions or aliasing anymore.
SFM on the ResultSet
Because the RecordMapperProvider works on the record that we don’t need we are not as performant as working directly with the ResultSet. Fortunately, jOOQ allows you to fetch the ResultSet directly avoiding the cost of the transition from ResultSet to Record.
That will allow you to get the query generation power of jOOQ and the close to pure Jdbc performance of SimpleFlatMapper.
The join aggregation is only available when using SFM on the result set as the RecordMapper interface expect one object per row.