CLEARSELECT statement

Syntax

CLEARSELECT [ALL | list.number]

Description

Use the CLEARSELECT statement to clear an active select list. This statement is normally used when one or more select lists have been generated but are no longer needed. Clearing select lists prevents remaining select list entries from being used erroneously.

Use the keyword ALL to clear all active select lists. Use list.number to specify a numbered select list to clear. list.number must be a numeric value from 0 through 10. If neither ALL nor list.number is specified, select list 0 is cleared.

If list.number evaluates to the null value, the CLEARSELECT statement fails and the program terminates with a run-time error message.

PICK, REALITY, and IN2 Flavors

PICK, REALITY, and IN2 flavor accounts store select lists in list variables instead of numbered select lists. In those accounts, and in programs that use the VAR.SELECT option of the $OPTIONS statement, the syntax of CLEARSELECT is:

CLEARSELECT [ALL | list.variable]

Example

The following program illustrates the use of CLEARSELECT to clear a partially used select list. The report is designed to display the first 40-odd hours of lessons. A CLEARSELECT is used so that all the selected records are not printed. Once the select list is cleared, the READNEXT statement ELSE clause is executed.

OPEN 'SUN.SPORT' TO FILE ELSE STOP "CAN'T OPEN FILE"
HOURS=0
*
EXECUTE 'SSELECT SUN.SPORT BY START BY INSTRUCTOR'
*
START:
READNEXT KEY ELSE
   PRINT 'FIRST WEEK', HOURS
   STOP
END
READ MEMBER FROM FILE,KEY ELSE GOTO START:
HOURS=HOURS+MEMBER<4>
PRINT MEMBER<1>,MEMBER<4>
IF HOURS>40 THEN
   ******
   CLEARSELECT
   ******
   GOTO START:
END
GOTO START:
END

This is the program output:

14 records selected to Select List #0
4309     1
6100     4
3452     3
6783     12
5390     9
4439     4
6203     14
FIRST WEEK         47