Re: what happens if a failed transaction is not rolled back?

On 4/24/23 08:43, Adrian Klaver wrote:
> On 4/24/23 08:37, Siddharth Jain wrote:
>> Hi All,
>>
>> i understand when writing application code, we should rollback a
>> transaction that fails to commit. this is typically done in the catch
>> block of a try-catch exception handler. but what if the developer does
>> not rollback the transaction? what happens in that case?
>>
>> note that i am not asking: what happens if a transaction is not rolled
>> back?
>> i am asking: what happens if a /failed/ transaction is not rolled back?
>>
>> failed transaction = you try to commit it but get an exception back
>> from the database.
>
> In Python:
>
> import psycopg2
> con = psycopg2.connect("dbname=test host=localhost  user=postgres")
> cur = con.cursor()
> cur.execute("select 1/0")
> DivisionByZero: division by zero
>
> cur.execute("select 1")
> InFailedSqlTransaction: current transaction is aborted, commands ignored
> until end of transaction block

Forgot to add.

To get past above:

con.rollback()
cur.execute("select 1")

>
>
>
>>
>> thanks.
>>
>> S.
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com