Обсуждение: Exception-handling

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Exception-handling

От
Håkan Jacobsson
Дата:
Hi,

I'm working against a postgresql database (version 8.0 ).
I was wondering how to handle exceptions properly when doing
database-related stuff, like queries, inserts etc.

Often when I get an exception (I just catch an SQL exception in the catch
clause) I get a message saying call getNextException(). Should I always add
this code in the catch clause? Or should I always add a catch for catching
postgresql-exceptions? Is there a general rule for this?

Re: Exception-handling

От
Dave Cramer
Дата:
The only general rule I adhere to is to make sure you clean up your
connections in a finally clause

Dave
On 21-Dec-06, at 5:01 AM, Håkan Jacobsson wrote:

> Hi,
>
> I'm working against a postgresql database (version 8.0 ).
> I was wondering how to handle exceptions properly when doing
> database-related stuff, like queries, inserts etc.
>
> Often when I get an exception (I just catch an SQL exception in the
> catch
> clause) I get a message saying call getNextException(). Should I
> always add
> this code in the catch clause? Or should I always add a catch for
> catching
> postgresql-exceptions? Is there a general rule for this?
>
>
>
> ---------------------------(end of
> broadcast)---------------------------
> TIP 7: You can help support the PostgreSQL project by donating at
>
>                 http://www.postgresql.org/about/donate
>

Re: Exception-handling

От
Roland Walter
Дата:
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Dave Cramer wrote:
> The only general rule I adhere to is to make sure you clean up your
> connections in a finally clause
>
> Dave

Depends of your application. I usually free up all resources in the
finally clause, that I do not need any more. The resources are
ResultSets and Statements and may be connections. Not closing the
Statments and using the same connection further prooved to be fatal.

Regards,
Roland.

- --
Dipl.-Phys. Roland Walter
mailto: roland (dot) walter (dot) rwa (at) gmx (dot) net
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Re: Exception-handling

От
Dave Cramer
Дата:
On 21-Dec-06, at 12:04 PM, Roland Walter wrote:

> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Dave Cramer wrote:
>> The only general rule I adhere to is to make sure you clean up your
>> connections in a finally clause
>>
>> Dave
>
> Depends of your application. I usually free up all resources in the
> finally clause, that I do not need any more. The resources are
> ResultSets and Statements and may be connections. Not closing the
> Statments and using the same connection further prooved to be fatal.

My point was to make sure you do your cleanup, whatever it may be in
a finally clause. This is the most frequent cause of leaking resources.

Dave
>
> Regards,
> Roland.
>
> - --
> Dipl.-Phys. Roland Walter
> mailto: roland (dot) walter (dot) rwa (at) gmx (dot) net
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>
> iD8DBQFFir6oxoOEAkary1ERAh1gAJ0XCLT7ildof8QbH/x6y+xrPy4xvACeLBwk
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>