Deferred validation exception handling : HOWTO ?
I need to knw if it's possible and how in a 2 and or 3 tier environment collect all exception and send them back to the client in one bounce.
It could be usefull in order to keep all "validation" error during a "validatio cycle" and rethrow them at
the end.
I don't mean at commit but every time the system start a validation (wich means going to a new row it validates the old row, at commit it validates all, at a setAttribute it validate the attribute).
Could someone help ?
TIA
Tullio
Tullio,
it depends on the validation error. If you have enetered a row that requires a field to be enetered but you didn't then you better have the user correcting this immediately.
Otherwise you can intercept the Exception and store it to somewhere else before at some point in time you throw it. There is a good paper on business rules that may anwer the question for validations to.
http://otn.oracle.com/products/jdev/htdocs/bc4j/BusinessRulesInBc4j.pdf
There also is one paper on validation in JClient (remembering that your last postings were about JClient)
http://otn.oracle.com/products/jdev/howtos/JClient/jclient_validation.html
Similar Messages
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May I use Exception Handling for validation ?
Hello All,
Can any one know about that may i use exception handling for validation in my report program.
Please if its possible then give me some Example...
Thanks.Hi Niraj,
Exception is not at all raised or handled in the given example.
There are so many document available in the SCN regarding OO ABAP you can read that.
As far as validation of a field ( Selection screen ) of course we can do that but I don't see any advantage more over it will make your code unnecessarily complex.
Regards
Bikas -
Exception generated during defered local transaction handling
Hi All,
We are using data direct connect 3.3 driver with MS SQL Server 7 on WebSphere 4.0. We are getting the exception "Exception generated during defered local transaction handling". Anyone encountered similar problem?> please let me know the solution. I am pasting the stack trace here.
Thanks in advance.
Regards,
Girish
[7/29/05 9:19:31:210 EDT] 37c1f1 SystemOut U 2005-07-29 09:19:31,177 [Servlet.Engine.Transports:10] ERROR com.xyz.nuuw.bus.dao.JDBCWrapper -livdsqa11122643171177
java.sql.SQLException: [IBM][SQLServer JDBC Driver]Exception generated during defered local transaction handling. See next exception via SQLException.getNextException for details.
at com.ibm.websphere.jdbc.base.BaseExceptions.createException(Unknown Source)
at com.ibm.websphere.jdbc.base.BaseExceptions.getException(Unknown Source)
at com.ibm.websphere.jdbc.base.BaseExceptions.getException(Unknown Source)
at com.ibm.websphere.jdbc.base.BaseConnection.transactionableWorkStarting(Unknown Source)
at com.ibm.websphere.jdbc.base.BaseStatement.commonExecute(Unknown Source)
at com.ibm.websphere.jdbc.base.BaseStatement.executeQueryInternal(Unknown Source)
at com.ibm.websphere.jdbc.base.BasePreparedStatement.executeQuery(Unknown Source)
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Doug -
PL/SQL 101 : Exception Handling
Frequently I see questions and issues around the use of Exception/Error Handling in PL/SQL. More often than not the issue comes from the questioners misunderstanding about how PL/SQL is constructed and executed, so I thought I'd write a small article covering the key concepts to give a clear picture of how it all hangs together. (Note: the examples are just showing examples of the exception handling structure, and should not be taken as truly valid code for ways of handling things)
Exception Handling
Contents
1. Understanding Execution Blocks (part 1)
2. Execution of the Execution Block
3. Exceptions
4. Understanding Execution Blocks (part 2)
5. How to continue exection of statements after an exception
6. User defined exceptions
7. Line number of exception
8. Exceptions within code within the exception block
1. Understanding Execution Blocks (part 1)
The first thing that one needs to understand is almost taking us back to the basics of PL/SQL... how a PL/SQL execution block is constructed.
Essentially an execution block is made of 3 sections...
+---------------------------+
| Declaration Section |
+---------------------------+
| Statements Section |
+---------------------------+
| Exception Section |
+---------------------------+
The Declaration section is the part defined between the PROCEDURE/FUNCTION header or the DECLARE keyword (for anonymous blocks) and the BEGIN keyword. (Optional section)
The Statements section is where your code goes and lies between the BEGIN keyword and the EXCEPTION keyword (or END keyword if there is no EXCEPTION section). (Mandatory section)
The Exception section is where any exception handling goes and lies between the EXCEPTION keyword at the END keyword. (Optional section)
Example of an anonymous block...
DECLARE
.. declarative statements go here ..
BEGIN
.. code statements go here ..
EXCEPTION
.. exception handlers go here ..
END;
Example of a procedure/function block...
[CREATE OR REPLACE] (PROCEDURE|FUNCTION) <proc or fn name> [(<parameters>)] [RETURN <datatype>] (IS|AS)
.. declarative statements go here ..
BEGIN
.. code statements go here ..
EXCEPTION
.. exception handlers go here ..
END;
(Note: The same can also be done for packages, but let's keep it simple)
2. Execution of the Execution Block
This may seem a simple concept, but it's surprising how many people have issues showing they haven't grasped it. When an Execution block is entered, the declaration section is processed, creating a scope of variables, types , cursors, etc. to be visible to the execution block and then execution enters into the Statements section. Each statment in the statements section is executed in turn and when the execution completes the last statment the execution block is exited back to whatever called it.
3. Exceptions
Exceptions generally happen during the execution of statements in the Statements section. When an exception happens the execution of statements jumps immediately into the exception section. In this section we can specify what exceptions we wish to 'capture' or 'trap' and do one of the two following things...
(Note: The exception section still has access to all the declared items in the declaration section)
3.i) Handle the exception
We do this when we recognise what the exception is (most likely it's something we expect to happen) and we have a means of dealing with it so that our application can continue on.
Example...
(without the exception handler the exception is passed back to the calling code, in this case SQL*Plus)
SQL> ed
Wrote file afiedt.buf
1 declare
2 v_name VARCHAR2(20);
3 begin
4 select ename
5 into v_name
6 from emp
7 where empno = &empno;
8 dbms_output.put_line(v_name);
9* end;
SQL> /
Enter value for empno: 123
old 7: where empno = &empno;
new 7: where empno = 123;
declare
ERROR at line 1:
ORA-01403: no data found
ORA-06512: at line 4
(with an exception handler, we capture the exception, handle it how we want to, and the calling code is happy that there is no error for it to report)
SQL> ed
Wrote file afiedt.buf
1 declare
2 v_name VARCHAR2(20);
3 begin
4 select ename
5 into v_name
6 from emp
7 where empno = &empno;
8 dbms_output.put_line(v_name);
9 exception
10 when no_data_found then
11 dbms_output.put_line('There is no employee with this employee number.');
12* end;
SQL> /
Enter value for empno: 123
old 7: where empno = &empno;
new 7: where empno = 123;
There is no employee with this employee number.
PL/SQL procedure successfully completed.
3.ii) Raise the exception
We do this when:-
a) we recognise the exception, handle it but still want to let the calling code know that it happened
b) we recognise the exception, wish to log it happened and then let the calling code deal with it
c) we don't recognise the exception and we want the calling code to deal with it
Example of b)
SQL> ed
Wrote file afiedt.buf
1 declare
2 v_name VARCHAR2(20);
3 v_empno NUMBER := &empno;
4 begin
5 select ename
6 into v_name
7 from emp
8 where empno = v_empno;
9 dbms_output.put_line(v_name);
10 EXCEPTION
11 WHEN no_data_found THEN
12 INSERT INTO sql_errors (txt)
13 VALUES ('Search for '||v_empno||' failed.');
14 COMMIT;
15 RAISE;
16* end;
SQL> /
Enter value for empno: 123
old 3: v_empno NUMBER := &empno;
new 3: v_empno NUMBER := 123;
declare
ERROR at line 1:
ORA-01403: no data found
ORA-06512: at line 15
SQL> select * from sql_errors;
TXT
Search for 123 failed.
SQL>
Example of c)
SQL> ed
Wrote file afiedt.buf
1 declare
2 v_name VARCHAR2(20);
3 v_empno NUMBER := &empno;
4 begin
5 select ename
6 into v_name
7 from emp
8 where empno = v_empno;
9 dbms_output.put_line(v_name);
10 EXCEPTION
11 WHEN no_data_found THEN
12 INSERT INTO sql_errors (txt)
13 VALUES ('Search for '||v_empno||' failed.');
14 COMMIT;
15 RAISE;
16 WHEN others THEN
17 RAISE;
18* end;
SQL> /
Enter value for empno: 'ABC'
old 3: v_empno NUMBER := &empno;
new 3: v_empno NUMBER := 'ABC';
declare
ERROR at line 1:
ORA-06502: PL/SQL: numeric or value error: character to number conversion error
ORA-06512: at line 3
SQL> select * from sql_errors;
TXT
Search for 123 failed.
SQL>
As you can see from the sql_errors log table, no log was written so the WHEN others exception was the exception that raised the error to the calling code (SQL*Plus)
4. Understanding Execution Blocks (part 2)
Ok, so now we understand the very basics of an execution block and what happens when an exception happens. Let's take it a step further...
Execution blocks are not just a single simple block in most cases. Often, during our statements section we have a need to call some reusable code and we do that by calling a procedure or function. Effectively this nests the procedure or function's code as another execution block within the current statement section so, in terms of execution, we end up with something like...
+---------------------------------+
| Declaration Section |
+---------------------------------+
| Statements Section |
| . |
| +---------------------------+ |
| | Declaration Section | |
| +---------------------------+ |
| | Statements Section | |
| +---------------------------+ |
| | Exception Section | |
| +---------------------------+ |
| . |
+---------------------------------+
| Exception Section |
+---------------------------------+
Example... (Note: log_trace just writes some text to a table for tracing)
SQL> create or replace procedure a as
2 v_dummy NUMBER := log_trace('Procedure A''s Declaration Section');
3 begin
4 v_dummy := log_trace('Procedure A''s Statement Section');
5 v_dummy := 1/0; -- cause an exception
6 exception
7 when others then
8 v_dummy := log_trace('Procedure A''s Exception Section');
9 raise;
10 end;
11 /
Procedure created.
SQL> create or replace procedure b as
2 v_dummy NUMBER := log_trace('Procedure B''s Declaration Section');
3 begin
4 v_dummy := log_trace('Procedure B''s Statement Section');
5 a; -- HERE the execution passes to the declare/statement/exception sections of A
6 exception
7 when others then
8 v_dummy := log_trace('Procedure B''s Exception Section');
9 raise;
10 end;
11 /
Procedure created.
SQL> exec b;
BEGIN b; END;
ERROR at line 1:
ORA-01476: divisor is equal to zero
ORA-06512: at "SCOTT.B", line 9
ORA-06512: at line 1
SQL> select * from code_trace;
TXT
Procedure B's Declaration Section
Procedure B's Statement Section
Procedure A's Declaration Section
Procedure A's Statement Section
Procedure A's Exception Section
Procedure B's Exception Section
6 rows selected.
SQL>
Likewise, execution blocks can be nested deeper and deeper.
5. How to continue exection of statements after an exception
One of the common questions asked is how to return execution to the statement after the one that created the exception and continue on.
Well, firstly, you can only do this for statements you expect to raise an exception, such as when you want to check if there is no data found in a query.
If you consider what's been shown above you could put any statement you expect to cause an exception inside it's own procedure or function with it's own exception section to handle the exception without raising it back to the calling code. However, the nature of procedures and functions is really to provide a means of re-using code, so if it's a statement you only use once it seems a little silly to go creating individual procedures for these.
Instead, you nest execution blocks directly, to give the same result as shown in the diagram at the start of part 4 of this article.
SQL> ed
Wrote file afiedt.buf
1 create or replace procedure b (p_empno IN VARCHAR2) as
2 v_dummy NUMBER := log_trace('Procedure B''s Declaration Section');
3 begin
4 v_dummy := log_trace('Procedure B''s Statement Section');
5 -- Here we start another execution block nested in the first one...
6 declare
7 v_dummy NUMBER := log_trace('Nested Block Declaration Section');
8 begin
9 v_dummy := log_trace('Nested Block Statement Section');
10 select empno
11 into v_dummy
12 from emp
13 where empno = p_empno; -- Note: the parameters and variables from
parent execution block are available to use!
14 exception
15 when no_data_found then
16 -- This is an exception we can handle so we don't raise it
17 v_dummy := log_trace('No employee was found');
18 v_dummy := log_trace('Nested Block Exception Section - Exception Handled');
19 when others then
20 -- Other exceptions we can't handle so we raise them
21 v_dummy := log_trace('Nested Block Exception Section - Exception Raised');
22 raise;
23 end;
24 -- ...Here endeth the nested execution block
25 -- As the nested block handled it's exception we come back to here...
26 v_dummy := log_trace('Procedure B''s Statement Section Continued');
27 exception
28 when others then
29 -- We'll only get to here if an unhandled exception was raised
30 -- either in the nested block or in procedure b's statement section
31 v_dummy := log_trace('Procedure B''s Exception Section');
32 raise;
33* end;
SQL> /
Procedure created.
SQL> exec b(123);
PL/SQL procedure successfully completed.
SQL> select * from code_trace;
TXT
Procedure B's Declaration Section
Procedure B's Statement Section
Nested Block Declaration Section
Nested Block Statement Section
No employee was found
Nested Block Exception Section - Exception Handled
Procedure B's Statement Section Continued
7 rows selected.
SQL> truncate table code_trace;
Table truncated.
SQL> exec b('ABC');
BEGIN b('ABC'); END;
ERROR at line 1:
ORA-01722: invalid number
ORA-06512: at "SCOTT.B", line 32
ORA-06512: at line 1
SQL> select * from code_trace;
TXT
Procedure B's Declaration Section
Procedure B's Statement Section
Nested Block Declaration Section
Nested Block Statement Section
Nested Block Exception Section - Exception Raised
Procedure B's Exception Section
6 rows selected.
SQL>
You can see from this that, very simply, the code that we expected may have an exception was able to either handle the exception and return to the outer execution block to continue execution, or if an unexpected exception occurred then it was able to be raised up to the outer exception section.
6. User defined exceptions
There are three sorts of 'User Defined' exceptions. There are logical situations (e.g. business logic) where, for example, certain criteria are not met to complete a task, and there are existing Oracle errors that you wish to give a name to in order to capture them in the exception section. The third is raising your own exception messages with our own exception numbers. Let's look at the first one...
Let's say I have tables which detail stock availablility and reorder levels...
SQL> select * from reorder_level;
ITEM_ID STOCK_LEVEL
1 20
2 20
3 10
4 2
5 2
SQL> select * from stock;
ITEM_ID ITEM_DESC STOCK_LEVEL
1 Pencils 10
2 Pens 2
3 Notepads 25
4 Stapler 5
5 Hole Punch 3
SQL>
Now, our Business has told the administrative clerk to check stock levels and re-order anything that is below the re-order level, but not to hold stock of more than 4 times the re-order level for any particular item. As an IT department we've been asked to put together an application that will automatically produce the re-order documents upon the clerks request and, because our company is so tight-ar*ed about money, they don't want to waste any paper with incorrect printouts so we have to ensure the clerk can't order things they shouldn't.
SQL> ed
Wrote file afiedt.buf
1 create or replace procedure re_order(p_item_id NUMBER, p_quantity NUMBER) is
2 cursor cur_stock_reorder is
3 select s.stock_level
4 ,r.stock_level as reorder_level
5 ,(r.stock_level*4) as reorder_limit
6 from stock s join reorder_level r on (s.item_id = r.item_id)
7 where s.item_id = p_item_id;
8 --
9 v_stock cur_stock_reorder%ROWTYPE;
10 begin
11 OPEN cur_stock_reorder;
12 FETCH cur_stock_reorder INTO v_stock;
13 IF cur_stock_reorder%NOTFOUND THEN
14 RAISE no_data_found;
15 END IF;
16 CLOSE cur_stock_reorder;
17 --
18 IF v_stock.stock_level >= v_stock.reorder_level THEN
19 -- Stock is not low enough to warrant an order
20 DBMS_OUTPUT.PUT_LINE('Stock has not reached re-order level yet!');
21 ELSE
22 IF v_stock.stock_level + p_quantity > v_stock.reorder_limit THEN
23 -- Required amount is over-ordering
24 DBMS_OUTPUT.PUT_LINE('Quantity specified is too much. Max for this item: '
||to_char(v_stock.reorder_limit-v_stock.stock_level));
25 ELSE
26 DBMS_OUTPUT.PUT_LINE('Order OK. Printing Order...');
27 -- Here goes our code to print the order
28 END IF;
29 END IF;
30 --
31 exception
32 WHEN no_data_found THEN
33 CLOSE cur_stock_reorder;
34 DBMS_OUTPUT.PUT_LINE('Invalid Item ID.');
35* end;
SQL> /
Procedure created.
SQL> exec re_order(10,100);
Invalid Item ID.
PL/SQL procedure successfully completed.
SQL> exec re_order(3,40);
Stock has not reached re-order level yet!
PL/SQL procedure successfully completed.
SQL> exec re_order(1,100);
Quantity specified is too much. Max for this item: 70
PL/SQL procedure successfully completed.
SQL> exec re_order(2,50);
Order OK. Printing Order...
PL/SQL procedure successfully completed.
SQL>
Ok, so that code works, but it's a bit messy with all those nested IF statements. Is there a cleaner way perhaps? Wouldn't it be nice if we could set up our own exceptions...
SQL> ed
Wrote file afiedt.buf
1 create or replace procedure re_order(p_item_id NUMBER, p_quantity NUMBER) is
2 cursor cur_stock_reorder is
3 select s.stock_level
4 ,r.stock_level as reorder_level
5 ,(r.stock_level*4) as reorder_limit
6 from stock s join reorder_level r on (s.item_id = r.item_id)
7 where s.item_id = p_item_id;
8 --
9 v_stock cur_stock_reorder%ROWTYPE;
10 --
11 -- Let's declare our own exceptions for business logic...
12 exc_not_warranted EXCEPTION;
13 exc_too_much EXCEPTION;
14 begin
15 OPEN cur_stock_reorder;
16 FETCH cur_stock_reorder INTO v_stock;
17 IF cur_stock_reorder%NOTFOUND THEN
18 RAISE no_data_found;
19 END IF;
20 CLOSE cur_stock_reorder;
21 --
22 IF v_stock.stock_level >= v_stock.reorder_level THEN
23 -- Stock is not low enough to warrant an order
24 RAISE exc_not_warranted;
25 END IF;
26 --
27 IF v_stock.stock_level + p_quantity > v_stock.reorder_limit THEN
28 -- Required amount is over-ordering
29 RAISE exc_too_much;
30 END IF;
31 --
32 DBMS_OUTPUT.PUT_LINE('Order OK. Printing Order...');
33 -- Here goes our code to print the order
34 --
35 exception
36 WHEN no_data_found THEN
37 CLOSE cur_stock_reorder;
38 DBMS_OUTPUT.PUT_LINE('Invalid Item ID.');
39 WHEN exc_not_warranted THEN
40 DBMS_OUTPUT.PUT_LINE('Stock has not reached re-order level yet!');
41 WHEN exc_too_much THEN
42 DBMS_OUTPUT.PUT_LINE('Quantity specified is too much. Max for this item: '
||to_char(v_stock.reorder_limit-v_stock.stock_level));
43* end;
SQL> /
Procedure created.
SQL> exec re_order(10,100);
Invalid Item ID.
PL/SQL procedure successfully completed.
SQL> exec re_order(3,40);
Stock has not reached re-order level yet!
PL/SQL procedure successfully completed.
SQL> exec re_order(1,100);
Quantity specified is too much. Max for this item: 70
PL/SQL procedure successfully completed.
SQL> exec re_order(2,50);
Order OK. Printing Order...
PL/SQL procedure successfully completed.
SQL>
That's better. And now we don't have to use all those nested IF statements and worry about it accidently getting to code that will print the order out as, once one of our user defined exceptions is raised, execution goes from the Statements section into the Exception section and all handling of errors is done in one place.
Now for the second sort of user defined exception...
A new requirement has come in from the Finance department who want to have details shown on the order that show a re-order 'indicator' based on the formula ((maximum allowed stock - current stock)/re-order quantity), so this needs calculating and passing to the report...
SQL> ed
Wrote file afiedt.buf
1 create or replace procedure re_order(p_item_id NUMBER, p_quantity NUMBER) is
2 cursor cur_stock_reorder is
3 select s.stock_level
4 ,r.stock_level as reorder_level
5 ,(r.stock_level*4) as reorder_limit
6 ,(((r.stock_level*4)-s.stock_level)/p_quantity) as finance_factor
7 from stock s join reorder_level r on (s.item_id = r.item_id)
8 where s.item_id = p_item_id;
9 --
10 v_stock cur_stock_reorder%ROWTYPE;
11 --
12 -- Let's declare our own exceptions for business logic...
13 exc_not_warranted EXCEPTION;
14 exc_too_much EXCEPTION;
15 begin
16 OPEN cur_stock_reorder;
17 FETCH cur_stock_reorder INTO v_stock;
18 IF cur_stock_reorder%NOTFOUND THEN
19 RAISE no_data_found;
20 END IF;
21 CLOSE cur_stock_reorder;
22 --
23 IF v_stock.stock_level >= v_stock.reorder_level THEN
24 -- Stock is not low enough to warrant an order
25 RAISE exc_not_warranted;
26 END IF;
27 --
28 IF v_stock.stock_level + p_quantity > v_stock.reorder_limit THEN
29 -- Required amount is over-ordering
30 RAISE exc_too_much;
31 END IF;
32 --
33 DBMS_OUTPUT.PUT_LINE('Order OK. Printing Order...');
34 -- Here goes our code to print the order, passing the finance_factor
35 --
36 exception
37 WHEN no_data_found THEN
38 CLOSE cur_stock_reorder;
39 DBMS_OUTPUT.PUT_LINE('Invalid Item ID.');
40 WHEN exc_not_warranted THEN
41 DBMS_OUTPUT.PUT_LINE('Stock has not reached re-order level yet!');
42 WHEN exc_too_much THEN
43 DBMS_OUTPUT.PUT_LINE('Quantity specified is too much. Max for this item: '
||to_char(v_stock.reorder_limit-v_stock.stock_level));
44* end;
SQL> /
Procedure created.
SQL> exec re_order(2,40);
Order OK. Printing Order...
PL/SQL procedure successfully completed.
SQL> exec re_order(2,0);
BEGIN re_order(2,0); END;
ERROR at line 1:
ORA-01476: divisor is equal to zero
ORA-06512: at "SCOTT.RE_ORDER", line 17
ORA-06512: at line 1
SQL>
Hmm, there's a problem if the person specifies a re-order quantity of zero. It raises an unhandled exception.
Well, we could put a condition/check into our code to make sure the parameter is not zero, but again we would be wrapping our code in an IF statement and not dealing with the exception in the exception handler.
We could do as we did before and just include a simple IF statement to check the value and raise our own user defined exception but, in this instance the error is standard Oracle error (ORA-01476) so we should be able to capture it inside the exception handler anyway... however...
EXCEPTION
WHEN ORA-01476 THEN
... is not valid. What we need is to give this Oracle error a name.
This is done by declaring a user defined exception as we did before and then associating that name with the error number using the PRAGMA EXCEPTION_INIT statement in the declaration section.
SQL> ed
Wrote file afiedt.buf
1 create or replace procedure re_order(p_item_id NUMBER, p_quantity NUMBER) is
2 cursor cur_stock_reorder is
3 select s.stock_level
4 ,r.stock_level as reorder_level
5 ,(r.stock_level*4) as reorder_limit
6 ,(((r.stock_level*4)-s.stock_level)/p_quantity) as finance_factor
7 from stock s join reorder_level r on (s.item_id = r.item_id)
8 where s.item_id = p_item_id;
9 --
10 v_stock cur_stock_reorder%ROWTYPE;
11 --
12 -- Let's declare our own exceptions for business logic...
13 exc_not_warranted EXCEPTION;
14 exc_too_much EXCEPTION;
15 --
16 exc_zero_quantity EXCEPTION;
17 PRAGMA EXCEPTION_INIT(exc_zero_quantity, -1476);
18 begin
19 OPEN cur_stock_reorder;
20 FETCH cur_stock_reorder INTO v_stock;
21 IF cur_stock_reorder%NOTFOUND THEN
22 RAISE no_data_found;
23 END IF;
24 CLOSE cur_stock_reorder;
25 --
26 IF v_stock.stock_level >= v_stock.reorder_level THEN
27 -- Stock is not low enough to warrant an order
28 RAISE exc_not_warranted;
29 END IF;
30 --
31 IF v_stock.stock_level + p_quantity > v_stock.reorder_limit THEN
32 -- Required amount is over-ordering
33 RAISE exc_too_much;
34 END IF;
35 --
36 DBMS_OUTPUT.PUT_LINE('Order OK. Printing Order...');
37 -- Here goes our code to print the order, passing the finance_factor
38 --
39 exception
40 WHEN exc_zero_quantity THEN
41 DBMS_OUTPUT.PUT_LINE('Quantity of 0 (zero) is invalid.');
42 WHEN no_data_found THEN
43 CLOSE cur_stock_reorder;
44 DBMS_OUTPUT.PUT_LINE('Invalid Item ID.');
45 WHEN exc_not_warranted THEN
46 DBMS_OUTPUT.PUT_LINE('Stock has not reached re-order level yet!');
47 WHEN exc_too_much THEN
48 DBMS_OUTPUT.PUT_LINE('Quantity specified is too much. Max for this item: '
||to_char(v_stock.reorder_limit-v_stock.stock_level));
49* end;
SQL> /
Procedure created.
SQL> exec re_order(2,0);
Quantity of 0 (zero) is invalid.
PL/SQL procedure successfully completed.
SQL>
Lastly, let's look at raising our own exceptions with our own exception numbers...
SQL> ed
Wrote file afiedt.buf
1 create or replace procedure re_order(p_item_id NUMBER, p_quantity NUMBER) is
2 cursor cur_stock_reorder is
3 select s.stock_level
4 ,r.stock_level as reorder_level
5 ,(r.stock_level*4) as reorder_limit
6 ,(((r.stock_level*4)-s.stock_level)/p_quantity) as finance_factor
7 from stock s join reorder_level r on (s.item_id = r.item_id)
8 where s.item_id = p_item_id;
9 --
10 v_stock cur_stock_reorder%ROWTYPE;
11 --
12 exc_zero_quantity EXCEPTION;
13 PRAGMA EXCEPTION_INIT(exc_zero_quantity, -1476);
14 begin
15 OPEN cur_stock_reorder;
16 FETCH cur_stock_reorder INTO v_stock;
17 IF cur_stock_reorder%NOTFOUND THEN
18 RAISE no_data_found;
19 END IF;
20 CLOSE cur_stock_reorder;
21 --
22 IF v_stock.stock_level >= v_stock.reorder_level THEN
23 -- Stock is not low enough to warrant an order
24 [b]RAISE_APPLICATION_ERROR(-20000, 'Stock has not reached re-order level yet!');[/b]
25 END IF;
26 --
27 IF v_stock.stock_level + p_quantity > v_stock.reorder_limit THEN
28 -- Required amount is over-ordering
29its nice article, have put up this one the blog
site,Nah, I don't have time to blog, but if one of the other Ace's/Experts wants to copy it to a blog with reference back to here (and all due credit given ;)) then that's fine by me.
I'd go for a book like "Selected articles by OTN members" or something. Does anybody have a list of links of all those mentioned articles?Just these ones I've bookmarked...
Introduction to regular expressions ... by CD
When your query takes too long ... by Rob van Wijk
How to pipeline a function with a dynamic number of columns? by ascheffer
PL/SQL 101 : Exception Handling by BluShadow -
Validation Event Handler Not working with GTC Recon???
We have implemented a Validation Event Handler on user entity.
In the code we have implemented both the execute methods i.e. Orchestration andf Bulk Orchestration. We have created a UDF for Manager field and our validation handler checks whether the user in Manager UDF field is an Active user in OIM or not. In case the user is not an Active user, code will throw a Validation Failed Exception.
At the time of changing the Manager UDF value from the Console directly Validation Event Handler is getting triggered but with GTC Recon Validation Handler is not Working.
Previously i faced the same issue with the post process event handler but the problem get resoved when i implemented execute method with Bulk Orchestration. As per my understanding Bulk Orchestration exceute method gets called with GTC Recon and execute method with Orchestration gets called when changing the attribute value directly from the console.
In case of Validation Event Handler i have implemented both but still validation Event handler is not working with GTC.
Thanks in Advance....Any Help????
-
Exception handling in App. package PeopleCode
Hi,
I am accessing a table that is on remote database using DBLink for an update/insert operation using SQLExec. I am trying to implement exception handling to account for the scenario where the remote database is offline so that transaction can continue. However when I use the try-catch block in the app. package PeopleCode somehow the processing does not seem to move forward from the error. The App. pacakage code is triggered by the handler of the service operation. The goal is to simply skip the SQLExec if the table is not available. I am not sure if there is any limitation to the fatal SQL errors which the try-catch can handle.
As expected i get below error when running select on a view which has remote table in the SQL developer as remote database is down.
ORA-12514: TNS:listener does not currently know of service requested in connect descriptor
Has anyone enconutered similar issue with exception handling and best way to move forward in this scenario.
Any response is much appreciated.
Thanks,
GireeshI did this with PL/SQL once. Basically, you want to know if the remote database is available before you execute SQL against it. Here is my function. You can then SQLExec something like select 'x' from dual where my_package.link_available('the_link_name') = 1. If you get a result, then the db link is active. If you don't, it is not active.
FUNCTION LINK_AVAILABLE(pv_name VARCHAR2)
RETURN NUMBER AS
lv_result PLS_INTEGER;
lv_name VARCHAR2(128);
BEGIN
lv_name := UPPER(pv_name);
-- parameter check to avoid SQL injection with dynamic SQL below
-- if the following selects no rows, it will fall through to exception
-- and return 0;
SELECT 1
INTO lv_result
FROM ALL_DB_LINKS
WHERE DB_LINK = lv_name;
-- if we made it this far, then the parameter was a valid db link name
-- execute SQL to test
EXECUTE IMMEDIATE 'SELECT 1 FROM PS_INSTALLATION@' || lv_name INTO lv_result;
RETURN lv_result;
EXCEPTION
WHEN OTHERS THEN
RETURN 0;
END LINK_AVAILABLE; -
This question has been asked time and again, without any clear answers to it. I would appreciate if some one can help me on this.
I am developing a web application with the following architecture:
JSF page calls backing bean methods which calls the service methods. Now my service methods can throw different exceptions like ValidationException, BusinessException, SystemException etc.
Now, what i want to do is : If Validation/Business Exceptions are thrown show the error messages to the user on the same page from which the action was called. And if a SystemException is thrown navigate to a default error page.
How can i handle this thing? Any clues?Thanks for the reply BalusC,
I checked the log files (application log as well as server log) also and there is no other stack trace besides of the exception which i am throwing. Let me elaborate on the exact issue:
I am trying to handle concurrency issues in my application. For example, When two users simultaneously try to edit the same record, the user who first saves the changes successfully. Now when the second user tries to save the changes i want to show him a message that "This record has been modified after you opened it for edit. Please refresh your page and reapply the changes". To show this message i am throwing a BusinessException from my service, which in turn gets propagated to my saveAction method. The saveAction method needs to handle this exception and somehow should show the above message to the user.
To achieve this,
1. i tried catching the exception in my saveAction and added the necessary faces message to FacesContext object. But it does not work. Later i read the reason behind this too, that in the invoke application phase a new context will be created and the messages will not be available to it.
2. I then added the throws clause to my saveAction method, so that my default exception handler will handle it.
saveAction method signature :
public String saveAction () throws BusinessException {
//some code here for save
return null;
}This is my code for the ErrorHandler.jsp:
<body>
<h1 style="color: red">Error</h1><br/><%
// print stack trace.
ExceptionHandler exceptionHandler = new ExceptionHandler();
// unwrap ServletExceptions.
while (exception instanceof ServletException || exception instanceof FacesException ||
exception instanceof ApplicationException) {
if(exception instanceof ServletException) {
exception = ((ServletException) exception).getRootCause();
} else if(exception instanceof FacesException) {
exception = ((FacesException) exception).getCause();
} else if(exception instanceof ApplicationException) {
exception = ((ApplicationException) exception).getCause();
%><font color="red"><%=exceptionHandler.handleException(exception)%></font><br/></body>and this is my code for the handleException method defined in the ExceptionHandler.java:
public static String getMessage(final String msgKey, final Object args[]) {
String message = messages.getProperty(msgKey);
if(args != null) {
final String replaceArgs[] = (String[]) args;
for(int i = 0; i < replaceArgs.length; i++)
message = message.replaceFirst("{" + i + "}", replaceArgs);
return message;
public String handleException(final Throwable exception) {
logger.debug("handleException called..");
String errorMessage = "Unknown error occured.";
String stackTrace = "Stacktrace can not be found. Please check the logs for more details.";
String errorString = null;
final StringWriter stringWriter = new StringWriter();
if(exception != null) {
exception.printStackTrace (new PrintWriter (stringWriter));
stackTrace = stringWriter.toString();
errorMessage = getMessage(exception.getMessage(), null);
errorString = "<b>" + errorMessage + "</b> <br> </br> <br> <input id=\"show\" type=\"button\" value=\"Show Details >>\" onClick=\"toggle();\" /> <div id=\"errorStackTrace\" style=\"display:none;\" > <pre>" + stackTrace + "</pre> </div>";
return errorString;
With the help of this code, i am simply trying to navigate to the error page if an exception occurs and display the appropriate error message with the stacktrace.
The strange thing is, the ErrorHandler.jsp page correctly gets called, which in turn calls the handleException method which returns the formatted error string. (I checked this by adding log statements everywhere). But the system does not actually navigates to the ErrorHandler.jsp page and shows an alert with the following message : "Request error, status : 500 Internal Server Error message : "
Can someone help me figure out what exactly the problem is? -
Exception handling in CE Visual Composer 7.1
Hi,
I have modeled a CAF Business Object and a custom Find operation which looks for a custom key. After that, I have exposed that operation as Web service and consumed it in Visual Composer. It is working perfectly as long as the search key exists in the Business Object backend table. When an arbitrart search term e.g. 1234 which does not exist is given, an error message is displayed and the program logic is halted.
Error occured while executing the service: Error in connection: Could not execute Web service, consult your administrator
My requirement is that, is it possible for me to display a custom message such as "The ID does not exist. Please enter a valid ID".
Besides, is it possbile to bypass this service call if it is not working? In my scenario, this service is actually used to search for any existing data for a selected Customer. If there is no data, the user can proceed with a new definition. So, the above mentioned exception blocks the program flow and the user is not able to continue.
Thanks in advance for any suggestions or ideas.
Regards,
Joon MengI am not aware exception handling features of VC but instead of raising SOAP Fault you can also transfer log message which is user friendly to display.
Another thing, instead of throwing exeption handle it inside try block so that program do not halt abruptly but gracefully. It is always possible to bypass existing service call like you said if output of service is not input of another.
In other word do not map output directly but on the "Next" event of button which enable you to goto next screen to work.
Regards,
Gourav -
I require the following very basic functionality from a function.
Create or Replace function fnc_get_col3 (a in number, b in number)
return number
as
begin
return select col3 from TAB1 where col1 = a and col2 = b;
end fnc_get_util;
My question is that can I use the regular exception handling (like 'No data found' and 'Too many rows') in above function when i am using the return and select statement in same line
OR do i have to recreate this function as
Create or Replace function fnc_get_col3 (a in number, b in number)
return number
as
abc number(5);
begin
select col3 into abc from TAB1 where col1 = a and col2 = b;
return abc;
exception
when no data found then
dbms_ouput.put_line 'No data found'
end fnc_get_util;
Thanks in AdvanceWhy do you believe it is syntactically valid to return a value this way? The first function does not compile and cannot compile so there is no exception handling to discuss
SQL> create or replace function f1
2 return number
3 is
4 begin
5 return select count(*) from emp;
6 end;
7 /
Warning: Function created with compilation errors.
SQL> sho err
Errors for FUNCTION F1:
LINE/COL ERROR
5/10 PLS-00103: Encountered the symbol "SELECT" when expecting one of
the following:
( - + ; case mod new not null <an identifier>
<a double-quoted delimited-identifier> <a bind variable>
continue avg count current exists max min prior sql stddev
sum variance execute forall merge time timestamp interval
date <a string literal with character set specification>
<a number> <a single-quoted SQL string> pipe
<an alternatively-quoted string literal with character set
specification>
<an alternYou would need your SELECT statement to select data into a local variable and to return that local variable as you are doing in your second implementation. It would not make sense, however, to have an exception handler that simply uses DBMS_OUTPUT to display a message-- you should only catch an exception if you can do something meaningful with it.
Justin -
Exception Handling for Array Binding
Hi
1)
I am using a Stored Procedure.
I am using array binding and if i am sending an array of count 10 to be inserted in a table and only 9 got inserted,i deliberatly inserted one errorneous record in array, the count returned by ExecuteNonQuery() is 10.Why ?
How can i come to know exact number of rows inserted in table, how can i use Output variables, because the array bind count is 10 so if i add an output parameter it gives error ArrayBind count is wrong....
2)
Is it possible to roll back all the inserts if error occurs in any of the insert by Oracle engine.What it does is it inserts all correct records and leaves the errorneous record and doesn't even throw any exception or any message.
Answer - This can be achieved by using OracleTransaction and don't use Exception handling in procedure otherwise there wont be any exception thrown by procedure which is necessary to detect if an error occured during insert.If you use exception handling OracleEngine will insert correct rows and leave errorneous record and return count of inserted + non inserted records which is wrong.
Please help.
Message was edited by:
user556446
Message was edited by:
user556446You'll need to encapsulate your validation within it's own block as described below:
-- this will die on the first exception
declare
TYPE T_BADDATA_TEST IS TABLE OF VARCHAR2(1000) INDEX BY binary_integer ;
tbt T_BADDATA_TEST ;
aBadTypeFound exception ;
begin
tbt(0) := 'a';
tbt(1) := 'b';
tbt(2) := 'c';
for idx in tbt.first..tbt.last loop
if tbt(idx) = 'b' then
raise aBadTypeFound ;
else
dbms_output.put_line(tbt(idx));
end if ;
end loop ;
end ;--encapsulate the exception area in a begin/end block to handle the exception but continue on
declare
TYPE T_BADDATA_TEST IS TABLE OF VARCHAR2(1000) INDEX BY binary_integer ;
tbt T_BADDATA_TEST ;
aBadTypeFound exception ;
begin
tbt(0) := 'a';
tbt(1) := 'b';
tbt(2) := 'c';
for idx in tbt.first..tbt.last loop
BEGIN
if tbt(idx) = 'b' then
raise aBadTypeFound ;
else
dbms_output.put_line(tbt(idx));
end if ;
EXCEPTION
WHEN aBadTypeFound THEN
dbms_output.put_line(tbt(idx) || ' is bad data');
WHEN OTHERS THEN
dbms_output.put_line('exception');
END ;
end loop ;
end ;
output:
a
b is bad data
c
***/ -
I have a perplexing question.... I am in the midst of developing an APEX 4.0 application. Customer will NOT be going to4.1 for a while....I wish to have exception handling that will handle both APEX based interactions and some back-end Sql Loader activity.
I have built an Exception handler that has a supporting APEX page to display a more human compatible error page, but am trying to make the exception handler NOT try and call up a page and such if the exception it encounters is a trigger being fired when a # of rows are being bulked loaded..
Simply put.. In the exception handler, how can I have code branch around the fact I might NOT have an APEX application for it to display the error ...
What I'd love to find is an object or variable that tells me what I am running the PL/SQL under..
Thank you,
Tony Miller
Dallas, TxJari,
If I try running this from SQL Plus, I would assume it would crash due to fact I am NOT running under APEX and can NOT see the Application object that this function is based upon:
IS_SESSION_VALID Function
This function is a Boolean result obtained from executing the current application's authentication scheme to determine if a valid session exists. This function returns the Boolean result of the authentication scheme's page sentry.
Its like trying to figure out which came 1st, the chicken or the egg...
Thank you,
Tony Miller
Dallas, TX -
Hi there,
after playing a bit with external xml files provided by my
application i'm ready to go to the next topic on my ToDo-List.
How could one implement a good and stable technique for
exception handling? I'm talking about the interaction from spry to
our Web Framework which throws an error sometimes.
My current idea is that the server side framework could
return some kind of Error XML format which contains the exception
message and so on. This would require functions on client side to
precheck the server output.
Imho the best place for this is inside the XMLDataSet
constructor. When catching some bad XML file internal error
messages could be send using the already existing techniques OR by
providing an public function which then should be overriden by an
selfwritten one, e.g. to put it into my own `error box`.
Also, some kind of internal statemachine in XMLDataSet may
help a lot. That way each access to functions which aren't working
at the moment could be loggend and catched by an selfwritten
function.
I hope you get the idea,
what do you think?
Best regards,
SebastianBetter error handling and error handling hooks is on the list
of things to do.
The way I see it, there are several types of errors that can
occur:
1. Server returns valid XML, but it's XML that describes an
error instead of the data requested.
- I believe this is what Sebastian was mentioning. I was
actually thinking of allowing a hook for developers to catch and
handle this case and perhaps leverage the states mechanism to let
them change the dynamic region markup used to display the error
since the data references in this error XML would be different.
2. The server returns an error. (Invalid URL or Server Error)
- This could be handled with states, but we need to expose
some data references, or set the data set to contain a known data
set schema that would allow the designer to show more info about
the error.
3. The server returns XML but uses a mime-type that is not
understood by Spy or the XML parsing code built-into the browser.
- I believe it was Doug [?] that had a patch that *always*
forced the data set to try and parse the XML string in the response
if the response didn't contain an XML DOM. My one paranoia about
that is that the server could actually be returning something that
is not XML, in which we would still fail and perhaps choke
somewhere else. I need to do some testing in that area.
I was thinking perhaps we should add something to the
XMLDataSet constructor that allowed a user to specify mime-types
for formats they knew were XML, but didn't use one of the standard
XML formats.
4. The browser chokes on "not-well-formed" XML.
- This is an interesting problem. IE silently fails when the
parser chokes, but Mozilla creates an XML DOM tree that reports the
error which does *not* match the XML string from the request
response. I had to add code to spry to detect when this happens.
5. An exception is thrown during Spry processing of XML data.
- This will require more programming on our part to handle
more cases.
--== Kin ==-- -
Customised Exception handling class.....
Hello Friends,
I am working on a project for which I need to create my own exception handling class.
The reason I need this class is to catch any exceptions and get a customised error message
according to each exception and then be able to display those messages on web page.
some examples of the exception I want to catch and display appropriate message are..
1. a duplicate reord in db
2. wrong data type (this will deal with ints,doubles and strings data types)
3. date type validation ( to make sure its date object instead of a string)
and there are several more messages but if can get some help or idea from any one to design a class for the above errors I might be able to manage other errors as well.
greatly appreciate any respnses.First off, you can extend Exception:
public class MyException extends Exception {
}You can put some custom messages into the class:
public class MyException extends Exception {
public static final String DUPLICATE_RECORD = "Duplicate record in db",
WRONG_DATA_TYPE = "Wrong data type",
VALIDATION_ERROR = "Invalid data type";
}Then, have your constructors, which take a String as an argument, so they can get your 'presets' or a custom message:
public class MyException extends Exception {
public static final String DUPLICATE_RECORD = "Duplicate record in db",
WRONG_DATA_TYPE = "Wrong data type",
VALIDATION_ERROR = "Invalid data type";
public MyException(String message) {
super(message);
}You could also have a series of exception classes: DuplicateRecordException, WrongDataTypeException, ValidationException, etc. Hope that helps.
m -
Console Exception Handling. Allow another attempt for user before exiting
I am trying to implement a very simple program that prompts the user for info and reads in a few numbers. If the user accidentally enters a letter instead of a number I want the user to get another chance, not just execute the exception handler and exit the program (as it does now). I'd rather have the user get stuck in an endless loop waiting for valid input versus exiting on the first invalid entry.
The code I am using is something like this:
try{
System.out.println("Enter a number?");
int b=System.in.read();
char c=(char) b;
String s=String.valueOf(c);
p.setDummyValue(Integer.parseInt(s) ); //**Possible Exception Here
catch(NumberFormatException e) {
System.out.println("Invalid Input");
// *** I'd love to somehow return to the "Enter a number" line from here
catch(IOException e) {
//IO error code here
}Q: How can I implement the ability to allow a user to correct invalid input?
ThanksSomething like this should work:boolean numberValid = false;
while (!numberValid) {
try {
System.out.println("Enter a number?");
int b=System.in.read();
System.in.skip(System.in.available()); // skip carriage return
char c=(char) b;
String s=String.valueOf(c);
p.setDummyValue(Integer.parseInt(s));
numberValid = true;
} catch(NumberFormatException e) {
System.out.println("Invalid Input");
} catch(IOException e) {
//IO error code here
} -
I want to write an exception handler for forms error message ora-01403. The problem code is
PRAGMA Exception_Init (login_name_doesnt_exist, -01403);
It gives me an 'illegal oracle error number' when I compile. I've checked the specs and -01403 IS valid. It is an error for 'no data found' which is right for the way I'm trying to use it.
BTW It compiles OK when I use error code -01404
Anyone else had this problem?Cheers, that works fine.
Thanks a lot
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Other Side ([email protected]):
You see IMHO, for proc
"PRAGMA Exception_Init (login_name_doesnt_exist, -01403);"
you must give sqlcode value, not the one what's in the sqlerrm.
So, instead -01403 try to use 100
P.S. have a nice day.<HR></BLOCKQUOTE>
null
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