Re: Odd behavior with 'currval'

On 02/08/2018 08:09 AM, Steven Hirsch wrote:
> I have a body of code using JDBC to work with a PostgreSQL 9.6 database. 
> All tables use 'SERIAL' or 'BIGSERIAL' types to generate ids.  All are 
> working correctly in terms of using the next value as a default. 
> However, reading back the most recently applied (currval) value is 
> failing for one table, where it always returns '0'. Note that the table 
> data shows the expected value when queried by SELECT!  It is only the 
> currval() function that is wrong.  I am properly guarding for SQL 
> exceptions and none are being thrown.
> 
> The code being used in the failing case is not the slightest bit 
> different from the working cases in terms of structure and transaction 
> control - only the SQL, column count, etc. is different (but correctly 
> formed and in all other ways functional).

Can we see the table schema and the currval code?

Is there anything in the Postgres logs that might help?

> 
> I'm not sure where to start debugging this.  Can anyone give me even a 
> working theory to explain how returning a bogus value is possible?  When 
> I look at the sequences in pgAdmin, they are as expected in terms of 
> ownership, etc.  And, again, the table IS getting the correct value.
> 
> Thanks much for any ideas!
> 


-- 
Adrian Klaver
adrian.klaver@aklaver.com