Kbase P16934: How trap for NOT AVAILABLE NO-ERROR type condition on FOR EA
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
11/25/2003 |
|
Status: Unverified
GOAL:
How trap for NOT AVAILABLE NO-ERROR type condition on FOR EACH
FIX:
The FOR EACH statement is designed to have the following properties:
- record reading
- block property
- record scoping
It does not allow you to trap for the NOT AVAILABLE condition if
no records meet the selection criteria.
- PROGRESS treats this as a "normal" condition
- no error condition is triggered
- the procedure block processes the next statement following the END
of the FOR EACH block.
To provide a graceful message to the user that there
are no records meeting the selection criteria, or that the records
requested are locked and cannot be used at the current time, use
a REPEAT block with FIND NEXT with logic for handling the NOT
AVAILABLE condition using NO-ERROR as illustrated in the following
example code.
DEFINE VARIABLE user-choice AS CHAR LABEL "NAME SELECTION".
UPDATE user-choice WITH FRAME fe-fr.
FOR EACH customer EXCLUSIVE-LOCK USE-INDEX name
WHERE name BEGINS user-choice WITH TITLE " Using FOR EACH ":
DISPLAY name cust-num city st zip.
END.
UPDATE user-choice WITH FRAME r-fr COLUMN 40.
REPEAT WITH TITLE " Using REPEAT/FIND/NO-ERROR test ":
FIND NEXT customer EXCLUSIVE-LOCK USE-INDEX name
WHERE name BEGINS user-choice NO-ERROR.
IF LOCKED customer THEN
DO:
MESSAGE "That record is locked..
MESSAGE "Please select another" UPDATE user-choice.
FIND FIRST CUSTOMER EXCLUSIVE-LOCK USE-INDEX name NO-ERROR.
END.
ELSE
IF NOT AVAILABLE customer THEN
DO:
MESSAGE "No more records begin with that string.".
MESSAGE "Please select another" UPDATE user-choice.
FIND FIRST CUSTOMER EXCLUSIVE-LOCK USE-INDEX name NO-ERROR.
END.
ELSE
DISPLAY name cust-num city st zip.
END.