Genero BDL is used to write the code for a 4gl file
that retrieves the data from a database and outputs it to a report.
This BDL program contains:
- The Report
Driver, which specifies the data the report will include.
If you are retrieving data from database tables, for example, a database
cursor is defined to retrieve specific rows. The Report Driver stores
the database values in program variables, and sends these - one record
at a time - to the REPORT program block.
- The REPORT
program block, which specifies the control blocks for a report,
and sends the data to the Genero Report Engine. Variables can be defined
to allow calculations on the data values, which are output along with
the data values.
The Genero Report Engine uses the data and the Report Design document
(4rp - created using Genero Report Designer) to process the report
and output it, in accordance with the Reporting
API functions that have been called by the BDL program.
See Steps
to a Report for a complete outline of the reporting process.
Some
Tips for Legacy Report Designers provides information about
the correlation between Report Designer and traditional 4GL commands
in reports.
The OrderReport.4gl example program included
in the GRW demo Reports:
- Retrieves the data and outputs it to the Report Engine.
- Allows the user to select the desired
report and the output settings, by displaying a form (Configuration.42f)
for input.
- Uses the Reporting API function fgl_report_loadCurrentSettings() to
load the original settings from the 4rp file.
(Additional optional
functions can specify the changes to be made to those settings,
based on the user input. )
- Uses the Reporting API function fgl_report_commitCurrentSettings() to
commit the changes this program has made.
- The Form Design file for this form, (Configuration.4fd)
is one of the files in the GRW demo project,Reports.
See the Reporting
API for the specific functions that you can use to control
the output of a report; some examples are in Change
Report Output Options.