1. Week 7 March 8 SQL: Chronological Sort, SUBSTRing, ROUND
Dynamic SQL: Host and Lexical Reference Variables
Overview: Drill-down, Roll-up Reports

3. Chronological sort
Month sequence in the calendar
Order by the month’s sequence

4. Without Chronological Order

5. Length
Beginning position
SUBSTR captures only parts of a string

6. Without SUBSTR
Wasted space

7. ROUND rounds a number to a specified number of decimal places

8. Without ROUND

9. Order by Quarter

10. Dynamic SQL
As opposed to static SQL, dynamic SQL allows the user to specify parts of the query (i.e., column names, table names, conditions, etc.) during runtime
For example (static SQL):
SQL> select manufacturer_code, to_char(sales_month_97,'q'),
2 sum(sales_revenue_97), sum(sales_revenue_98)
3 from sales_97_98
4 where lower(manufacturer_code) = 'son'
5 group by manufacturer_code, to_char(sales_month_97,'q')
6 order by to_char(sales_month_97,'q');
The same columns, table and condition are used

11. Dynamic SQL
With dynamic SQL, parts of the query can be substituted by variable names
During run time, the user will specify a value for P_time_interval
Lexical reference variable name
Lexical reference variable designator
Host variable
select manufacturer_code, &P_Time_interval,
sum(sales_revenue_97), sum(sales_revenue_98)
from sales_97_98
where lower(manufacturer_code) = :P_manufacturer_code
group by manufacturer_code, to_char(sales_month_97,'q')
order by &P_Time_interval;
Host variable designator

12. Creating a Lexical Reference Variable
Create a lexical reference variable under User Parameters of the Data Model (in the Object Navigator)
Select 
Create

13. Create a User Parameter
Default name
Select the new parameter, right-mouse click and select Property Palette

14. Change the Properties Change the name
Change the data type to character
Assign an initial value (optional)

15. Insert the Lexical Reference Variables (User Parameters)

16. Lexical reference variables
During Runtime...
Host variable
Lexical reference variables
(default values)
Host variable

17. Drill-Down, Roll-up Reports
A drill-down report is actually two or more reports working together
The top-level report is like a master record
Launches a report that provides more details about the data in its current record
Generally, the detail report displays information related to the master
Provides details for a single record, a group of records, or the report as a whole
Master report "links" to the detail report by passing parameters that control the execution of the detail
Master
Detail

18. Drill-Down Reports Master Report (Annual) Data Model 1 Parameter-list1
(Quarters)
Data Model 2
Parameter-list2
Drill-down Report
(Months)
Data Model 2

19. + =

20. Annual

21. Quarters

22. Months within a Quarter