7.67.3 LEAVE Examples
Using LEAVE within a SELECT Loop
Using LEAVE within a BEGIN_LOOP loop
Using LEAVE within a SELECT Loop
At times, when one record has been read in a SELECT loop, there is no need to read further. This example demonstrates how to achieve this using the LEAVE command within a SELECT loop.
For example, assume you have a pricing file defined like this, sorted by these primary keys:
1. #ITEMNO (ascending).
2. #EFF_DATE (ascending).
|
Item No. |
Effective Date |
Price ($) |
|
116 |
2000/01/01 |
4.00 |
|
116 |
2000/07/01 |
4.25 |
|
116 |
2001/01/01 |
4.50 |
|
116 |
2001/07/01 |
4.75 |
|
116 |
2002/01/01 |
5.00 |
For the purpose of an invoice, a price for item 116 as at 08/02/2001 is required.
DEFINE FIELD(#REQITEM) REFFLD(#ITEMNO)
DEFINE FIELD(#REQDATE) REFFLD(#EFF_DATE)
DEFINE FIELD(#PRICEOUT) REFFLD(#PRICE)
BEGIN_LOOP
REQUEST FIELDS(#REQITEM #REQDATE)
CHANGE FIELD(#PRICEOUT) TO(0)
EXECUTE SUBROUTINE(GETPRICE) WITH_PARMS(#REQITEM #REQDATE #PRICEOUT)
DISPLAY FIELDS(#REQITEM #PRICEOUT)
END_LOOP
SUBROUTINE NAME(GETPRICE) PARMS((#REQITEM *RECEIVED) (#REQDATE *RECEIVED) (#PRICEOUT *RETURNED))
SELECT FIELDS(#ITEMNO #EFF_DATE #PRICE) FROM_FILE(PRICING) WHERE('#ITEMNO = #REQITEM') WITH_KEY(#REQITEM #REQDATE) OPTIONS(*BACKWARDS *STARTKEY *ENDWHERE)
CHANGE FIELD(#PRICEOUT) TO(#PRICE)
LEAVE
ENDSELECT
ENDROUTINE
The SELECT positions to the pricing record with an effective date the same as or earlier than the requested date and reads it. If a record is found, the value of #PRICE is moved into #PRICEOUT. As the required record has been found it is not necessary to keep reading pricing records, so the LEAVE is used to exit from the SELECT loop.
If no record is found for the requested item, prior to (or equal to ) the requested date, the value #PRICEOUT remains zero.
Alternatively, instead of requesting an 'as of' date today's date can be used automatically.
DEFINE FIELD(#REQITEM) REFFLD(#ITEMNO)
DEFINE FIELD(#PRICEOUT) REFFLD(#PRICE)
BEGIN_LOOP
REQUEST FIELDS(#REQITEM)
CHANGE FIELD(#PRICEOUT) TO(0)
EXECUTE SUBROUTINE(GETPRICE) WITH_PARMS(#REQITEM #PRICEOUT)
DISPLAY FIELDS(#REQITEM #PRICEOUT)
END_LOOP
SUBROUTINE NAME(GETPRICE) PARMS((#REQITEM *RECEIVED)(#PRICEOUT *RETURNED))
SELECT FIELDS(#ITEMNO #EFF_DATE #PRICE) FROM_FILE(PRICING) WHERE('#ITEMNO = #REQITEM') WITH_KEY(#REQITEM *YYYYMMDD) OPTIONS(*BACKWARDS *STARTKEY *ENDWHERE)
CHANGE FIELD(#PRICEOUT) TO(#PRICE)
LEAVE
ENDSELECT
ENDROUTINE
Using LEAVE within a BEGIN_LOOP loop
This example demonstrates how to use the LEAVE command within a BEGIN_LOOP loop. With the help of an additional user function key and a defined condition the LEAVE command causes the loop to end when the user presses the 'Finish' key.
DEF_COND NAME(*FINISHED) COND('#IO$KEY = ''09''')
DEF_LIST NAME(#EMPBROWSE) FIELDS(#EMPNO #SURNAME #GIVENAME)
BEGIN_LOOP
REQUEST FIELDS(#EMPNO #SURNAME #GIVENAME) BROWSELIST(#EMPBROWSE) USER_KEYS((09 'Finish'))
LEAVE IF(*FINISHED)
ADD_ENTRY TO_LIST(#EMPBROWSE)
END_LOOP
MESSAGE MSGTXT('Input of Employees Completed')