I want to use T-SQL to perform a sequence of merges. I understand that if one fails, it rolls back, but I would like to print a message to the effect - so I know I need to go and check it. I can't seem to find any examples of this to start with. My first thought was to put the the transaction in a try, but then I'm not sure what happens with the rollback statement ... it seems weird putting that in the catch. I'm sure others must have had wanted to do this previously. Does anyone have an example of this?
NOTE: I need to use the MERGE command.
Try below code. Try Catch help from msdn
BEGIN TRY
-- Table does not exist; object name resolution
-- error not caught.
SELECT * FROM Table;
END TRY
BEGIN CATCH
Print ERROR_NUMBER() ;
Print ERROR_MESSAGE() ;
END CATCH
You can use OUTPUT with a merge. Sample
Related
I'm looking at this example provided by MS as I'm trying to learn Try...Catch. I understand the syntax and Output (for the most part) but I have one question:
The Output will show the Error_Line as '4'. This is fine but if I remove the line break between GO and BEGIN TRY it'll show the Error_Line as '3'. I just want to understand the logic here.
What I imagine is happening is that SQL Server is counting the lines by beginning the batch immediately after GO, even if that line is blank but I do not know this for certain. Can anyone clarify? If that theory is correct, wouldn't that make finding errors difficult if scripts are written with line breaks like this?
-- Verify that the stored procedure does not already exist.
IF OBJECT_ID ( 'usp_GetErrorInfo', 'P' ) IS NOT NULL
DROP PROCEDURE usp_GetErrorInfo;
GO
-- Create procedure to retrieve error information.
CREATE PROCEDURE usp_GetErrorInfo
AS
SELECT
ERROR_NUMBER() AS ErrorNumber
,ERROR_SEVERITY() AS ErrorSeverity
,ERROR_STATE() AS ErrorState
,ERROR_PROCEDURE() AS ErrorProcedure
,ERROR_LINE() AS ErrorLine
,ERROR_MESSAGE() AS ErrorMessage;
GO
--Line 1
BEGIN TRY --Line 2
-- Generate divide-by-zero error. --Line 3
SELECT 1/0; --Line 4
END TRY
BEGIN CATCH
-- Execute error retrieval routine.
EXECUTE usp_GetErrorInfo;
END CATCH;
You can't really rely on ERROR_LINE(), especially when the error is thrown in internal stored procedure or there is dynamic T-SQL statement which is executed.
But do you really need the exact error line?
in real production code, the fix for the line causing the error may not be so obvious as in your example;
it will be better to debug the stored procedure or the function with the corresponding input parameter in order to reproduce the error
In this way it will be easier to fix an issue. In order to debug a SQL routine:
just script it
remove the drop and create stuff
add declare in front of the input parameters and initialized them with the values causing the error
Basically, instead of the exact error line (which can be easily fine having the correct input parameters and executing the routine) you may found useful two things:
which routing is causing the error (for example, you can add additional parameter to user usp_GetErrorInfo SP which is yielding the SP name as well
the input parameters which are causing the error (this can be done using separated table for logging the errors in the CATCH clause - you simple insert the input parameters in the table and information about the error)
Having this information, it will be easy to reproduce and then fix an issue (in many cases).
I have to make a update function that have multiple conditions like this
BEGIN
OPEN cur3 FOR execute('select id_organigramme from ( select distinct id_personne,id_organigramme,idfax from requpdate where
id_personne= ' || VariableIDpersonne || ' and idfax is null) a where
a.id_organigramme not in (select distinct id_organigramme from
requpdate where id_personne= ' ||VariableIDpersonne || ' and idfax is
not null and a.id_personne=requpdate.id_personne ) ');
LOOP
FETCH cur3 INTO VariableIDorganigrammeFax;
if not found then
--Message here !!!
--Raise notice 'hello word!'
exit;
end if;
I have to show up messages if any condition exists I found out that I can do this with Raise Notice/info ... statement, but I have to make auto export of those messages into a text file when the function finishes.
Is this possible? Otherwise what can I use to make it.
I use PGAdminIII as a client.
What your logging options are depends entirely on your client configuration. But rather than using RAISE NOTICE I would suggest you use the NOTIFY \ LISTEN framework. Basically, in your function you issue a notice to a channel of your choosing (can be any string) and in your client you listen to that same channel, logging the messages as they come in. How exactly the listening and logging works depends on your client.
The code you show can also you use some improvements.
First of all, your query is an incredibly convoluted version of:
SELECT DISTINCT id_organigramme
FROM requpdate
WHERE id_personne = VariableIDpersonne
AND idfax IS NULL;
Secondly, you do not need a dynamic query, you can get by with variable substitution. Assuming id_personne is not a string, it is as simple as stated above, otherwise use quote_literal(VariableIDpersonne).
Lastly, unless there are parts of your function not shown that require a cursor, you can simply do:
FOR VariableIDorganigrammeFax IN [query above]
LOOP
... -- do your processing here
END LOOP;
IF NOT FOUND THEN -- the loop above did not iterate because no records were returned
SELECT pg_notify('logMyFunction', format('%s: No records found', VariableIDpersonne));
END IF;
The pg_notify() function is a wrapper around the NOTIFY command that makes it possible to pass variable strings.
Before you call the function, you should issue the command LISTEN logMyFunction so that your session will receive the notifications from the channel.
I am using Sybase ASE 12.5 at the moment. I have a code below:
create procedure test_launcher_fail_wrapper
as
begin
select convert(numeric(2),1234345)
if ##error != 0
begin
select "SP failed to execute"
return 1
end
end
Here, I am trying to convert a very large value/amount (1234345) to Numeric size 2. Which is not possible and it generates error.
Questions:
Is having ##error useful here? I ran this SP and it never went into
error handling
How to error handle these kind of scenarios?
I treat error handling in procs similarly to error handling in applications -- if there's an opportunity for you to contribute some actual value by handling the error, then by all means, do so, but if you can't really do anything to help, then you're better off just letting it go.
As an example of adding value, I've got one or two procs that add contextual information in the error message, like a list of ID values that conflict with an update operation. In this particular case, I know that the upstream consumer of the proc will log this error, and the text will be available to an operator who will find this information valuable when debugging the problem. I also know that while this condition is a real error, it's been known to happen from time-to-time, and the effort to format the error is worthwhile.
Does this catch your error?
create procedure test_launcher_fail_wrapper
as
begin
declare #database_err int
set #database_err = 0
select convert(numeric(2),1234345)
set #database_err = ##error
if #database_err <> 0
begin
PRINT 'SP failed to execute'
return 1
end
end
##error is the way to go but beware since:
Every Transact-SQL statement, including print statements and if tests, resets ##error, so the status check must immediately follow the batch for which success is in question.
As for a suggestion on how to handle error management in similar scenarios, have you considered using raiserror ?
An example:
create procedure proc1 as
begin
select convert(numeric(2),1234345)
if ##error <> 0
begin
raiserror 20001 "Error during convert in proc1"
return 1
end
end
I'm developing a trigger that has to check the correctness of a date. I'm have big time trouble creating one, becase no matter how I try to simplify my code, Oracle returns me the same error: ORA-00922: missing or invalid option. I have checked the code over and over again and I really can't figure out where my issue is!
The following is an over-simplified version of the trigger, which gets the same error too.
CREATE OR REPLACE checkDateValidity
BEFORE INSERT
ON Event
FOR EACH ROW
BEGIN
IF :new.month>12
THEN
RAISE_APPLICATION_ERROR(-20101, 'Error: wrong month');
END IF;
END;
I really hope you can help me because at this point I really have no idea of what I am doing wrong.
You are missing the TRIGGER keyword:
CREATE OR REPLACE TRIGGER checkDateValidity
.... ^^^^^^^
I'm in a web scripting class, and honestly and unfortunately, it has come second to my networking and design and analysis classes. Because of this I find I encounter problems that may be mundane but can't find the solution to it easily.
I am writing a CGI form that is supposed to work with a MySQL DB. I can insert and delete into the DB just fine. My problem comes when querying the DB.
My code compiles fine and I don't get errors when trying to "display" the info in the DB through the browser but the data and text doesn't in fact display. The code in question is here:
print br, 'test';
my $dbh = DBI->connect("DBI:mysql:austinc4", "*******", "*******", {RaiseError => 1} );
my $usersstatement = "select * from users";
my $projstatment = "select * from projects";
# Get the handle
my $userinfo = $dbh->query($usersstatement);
my $projinfo = $dbh->query($projstatement);
# Fetch rows
while (#userrow = $userinfo->fetchrow()) {
print $userrow[0], br;
}
print 'end';
This code is in an if statement that is surrounded by the print header, start_html, form, /form, end_html. I was just trying to debug and find out what was happening and printed the statements test and end. It prints out test but doesn't print out end. It also doesn't print out the data in my DB, which happens to come before I print out end.
What I believe I am doing is:
Connecting to my DB
Forming a string the contains the command/request to the DB
Getting a handle for my query I perform on the DB
Fetching a row from my handle
Printing the first field in the row I fetched from my table
But I don't see why my data wouldn't print out as well as the end text. I looked in DB and it does in fact contain data in the DB and the table that I am trying to get data from.
This one has got me stumped, so I appreciate any help. Thanks again. =)
Solution:
I was using a that wasn't supported by the modules I was including. This leads me to another question. How can I detect errors like this? My program does in fact compile correctly and the webpage doesn't "break". Aside from me double checking that all the methods I do use are valid, do I just see something like text not being displayed and assume that an error like this occurred?
Upon reading the comments, the reason your program is broken is because query() does not execute an SQL query. Therefore you are probably calling an undefined subroutine unless this is a wrapper you have defined elsewhere.
Here is my original posting of helpful hints, which still apply:
I hope you have use CGI, use DBI, etc... and use CGI::Carp and use strict;
Look in /var/log/apache2/access.log or error.log for the bugs
Realize that the first thing a CGI script prints MUST be a valid header or the web server and browser become unhappy and often nothing else displays.
Because of #3 print the header first BEFORE you do anything, especially before you connect to the database where the script may die or print something else because otherwise the errors or other messages will be emitted before the header.
If you still don't see an error go back to #2.
CGIs that use CGI.pm can be run from a command line in a terminal session without going through the webserver. This is also a good way to debug.