EJBQL or ejbql set as their language. This mapping can be changed by using the related JasperReports
properties (see properties in the category
net.sf.jasperreports.query.executer.factory.{language}
).
net.sf.jasperreports.ejbql.query.hint.{hintName} as a hint by interpreting the property suffix as
the hint name and the property value as the hint value.]]>A separate report property can be used to paginate the query result in order to control the amount of Java heap space used by the query executer while filling the report. The property can be set in the following manner:
]]>meaning that the query result will be fetched in chunks containing 500 rows each. The pagination is achieved via the
javax.persistence.Query.setMaxResults()
and setFirstResult() methods. Obviously, using pagination could result in performance loss. Therefore enabling it is primarily recommended when the query
results are very large.
COLUMN_<index> - the field is mapped to a value specified by its position in the resulting tuple. The positions start from 1.COLUMN_<index>.<property> - the field is mapped to a property of a value specified by its position in the resulting tuple.demo/samples/ejbql directory is structured as follows:
data directory contains the SQL script that creates and populates the following tables in the built-in HSQL database:
PERSON - stores people IDs and namesMOVIE - stores movie ID, director, title, genre and release date informationsMOVIE_CAST - stores ID, movie ID, actor ID, character and role importanceMOVIE_VARIA - stores ID, movie ID, type, description, importancedocs directory contains the xml file used to generate this documentationlib directory contains 3-rd party jars with necessary persistence APIsreports directory contains, as usual, report templates (1 master and 2 subreports)src directory contains
META-INF subdirectory with the persistence.xml persistence configuration file:
oracle.toplink.essentials.ejb.cmp3.EntityManagerFactoryProvider Person Movie Cast Varia ]]>
Person, Movie, Cast and Varia.
Corresponding tables are specified in the @Table annotation:
EjbqlApp.java file that hosts the main method.reports/JRMDbReport.jrxml master report is structured to present movies in the database along with their additional informations, such as
casting, awards, quotes, etc. Casts are managed separately in the reports/JRMDbCastSubreport.jrxml template, and the rest of additional
information is provided by the reports/JRMDbVariaSubreport.jrxml
reports/JRMDbReport.jrxml, one could notice the specific hint properties, the EJB QL query syntax, report fields declarations
and how the subreports were set:
The Movie entities provide an... ... ...]]> ...
id, a director (who is a Person entity), a title,
a genre, releaseDate and a collection of cast entities. Notice the report field
director.name that refers to the name property in the director entity.
cast field is passed as a JRBeanCollectionDataSource to the casting subreport.
Varia subreport has no expression for data source/connection, but takes the built-in JPA_ENTITY_MANAGER parameter
into consideration, and the movie ID, in order to identify the Varia entities related to the movie.
reports/JRMDbCastSubreport.jrxml provides no query, because the data source comes already prepared here. There are two fields
declared in the report:
Again, the]]>
actor.name field references the name property in the actor entity of type Person.
reports/JRMDbVariaSubreport.jrxml one could notice the presence of an EJB QL query and field descriptions based on column positions:
Running the Sample... ]]>
ant is already installed on your system (version 1.5 or later).
demo/hsqldb within the JasperReports source project and run the > ant runServer command.
It will start the HSQLDB server shipped with the JasperReports distribution package. Let this terminal running the HSQLDB server.
demo/samples/ejbql within the JasperReports source project and run the > ant test view command.
demo/samples/ejbql/build/reports directory.