REFERENCE LIBRARY
RDS gives the programmer full control over how data is collected. RDS is not always necessary, but below are some examples in which RDS would be smart to use, or in some cases could not be done without.
The Data Access football pool application for example contains a number of web service functions. The DataFlex Reports OCX can’t read from this, because it can’t connect to this as a database.
Some of the functions return existing information, such as the number of yellow and red cards shown to a player. A DataFlex application can call from this web function, and process the return data into a RDS array. The DataFlex Reports OCX will format the data and produce the output.
What if by some smart logic the data can be overloaded to a SQL server, by using embedded SQL. The DataFlex application launches the SQL statement, converts the results into a RDS Array, which is then handled by the DFR OCX to produce the output.
You might know that photos taken with a digital camera contain metadata. This EXIF Data provides information about ISO, Exposure time, Aperture and much more, can be read by a DataFlex application. The application then converts the EXIF information into a RDS array, which is then processed by the DFR OCX to produce the output.
These are just three example of how RDS can be used, in the next lesson you will learn how this can be done.
