Publishing Reports to the Web - Downloads - Oracle

Methodology
Example
The following PL/SQL function can be stored in the Oracle9i database:
CREATE OR REPLACE FUNCTION CityState (
p_location_id world_cities.location_id%TYPE)
RETURN VARCHAR2 is
v_result VARCHAR2(100);
BEGIN
SELECT city || ‘,‘||state
INTO v_result
FROM world_cities
WHERE location_id = p_location_id;
RETURN v_result;
END CityState;
This function returns the city separated by a comma, a space, and the state. This
formatting is done at the database level and passed back to the report to display.
In the report, the SQL query would look like:
SELECT location_id, citystate(location_id)"City
& State" FROM world_cities
The result would look like this:
LOCATION_ID CITY & STATE
----------- -------------------------
1 Redwood Shores, California
2 Seattle, Washington
3 Los Angeles, California
4 New York, New York
20.1.2.4 Redundant Data
A report’s query should ideally select only required columns and not unrequired
columns (redundant query) as this affects performance. The fewer queries you have,
the faster your report will run. Single-query data models execute more quickly than
multi-query data models. However, situations can arise where a report not only needs
to produce a different format for different users, but also needs to utilize different
query statements. Although this can be achieved by producing two different reports, it
may be desirable to have a single report for easier maintenance. In this instance, the
redundant queries should be disabled using the SRW.SET_MAXROW() built-in
procedure.
Example
The following code used in the Before Report trigger will disable, either Query_Emp or
Query_Dept, depending on the user parameter:
IF :Parameter_1 = 'A' then
SRW.SET_MAXROW('Query_Emp',0);
ELSE
SRW.SET_MAXROW('Query_Dept',0);
END IF;
20-10 Oracle Application Server Reports Services Publishing Reports to the Web