Re: I think that my data is saved correctly, but when printing again, other data appears

[Yessica Brinkmann <yessica.brinkmann@xxxxxxxxx>]

Thank you so much for your answer. I will be testing the indicated and then I give you return.
Best regards,

Yessica Brinkmann

-------- Mensaje original --------
Asunto: Re: I think that my data is saved correctly, but when printing again, other data appears
De: Tom Lane
Para: Yessica Brinkmann
CC: pgsql-general@xxxxxxxxxxxxxxxxxxxx

Yessica Brinkmann writes:
> I have a function called get_columnnames, which runs on a Postgresql server
> and returns the names of the columns of a table in a Postgresql database.
> In the first foreach, in the statement: idxcd-> varattnames [cont] = data;
> column names are saved. Those column names are saved correctly. I could
> verify this by printing some values.
> But later, in the following foreach, when I reprint the values of the names
> of the columns that had been saved in the idxcd-> varattnames [cont] = data
> statement; They appear to me with errors.

Yeah, because the "data" value is just a pointer into the tupdesc
associated with the SPI result, and that disappears the moment you
do SPI_finish(). You'd need to do something to copy the strings
into a longer-lived context. A plain pstrdup() won't suffice
because you're in a short-lived SPI context already inside that
loop; but you could save CurrentMemoryContext before starting up
SPI and then use MemoryContextStrdup.

regards, tom lane