Re: type SERIAL in C host-struct

El día sábado, noviembre 09, 2019 a las 04:31:53p. m. +0100, Peter J. Holzer escribió:

> On 2019-11-07 20:14:47 +0100, Matthias Apitz wrote:
> > At the end of the day we came up with the following solution:
> >
> > strcpy(host_struct.name, "Sigrid");
> > EXEC SQL select nextval('lina_lid_seq') into :host_struct.ser;
> >
> > EXEC SQL INSERT INTO lina VALUES ( :host_struct );
> >
> > which seems to work fine. Any comments about side effects?
>
> You are performing two queries instead of one, so you have to wait for
> one extra round trip. Not a problem if client and server are on the same
> network or you insert a few host_structs per second. May be a problem if
> client and server are in different datacenters and you want to do
> hundreds of inserts per second.

Thanks for the feedback. Client and server run both on the same Linux
host. I found also the debug log of ESQL/C i.e. how to enable it with

ECPGdebug(int on, FILE *stream);

The resulting log is really fine for debugging our code:

[26301]: ECPGdebug: set to 1
[26301]: ECPGconnect: opening database newsisis on localhost port 5432 for user sisis
[26301]: prepare_common on line 49: name s_statename; query: "SELECT myint, mychar, mydate, myvchar, myblob FROM mytypes;"
[26301]: ecpg_execute on line 52: query: declare c_statename cursor for SELECT myint, mychar, mydate, myvchar, myblob FROM mytypes;; with 0 parameter(s) on connection newsisis
[26301]: ecpg_execute on line 52: using PQexec
[26301]: ecpg_process_output on line 52: OK: DECLARE CURSOR
[26301]: ecpg_execute on line 60: query: fetch in c_statename; with 0 parameter(s) on connection newsisis
[26301]: ecpg_execute on line 60: using PQexec
[26301]: ecpg_process_output on line 60: correctly got 1 tuples with 5 fields
[26301]: ecpg_get_data on line 60: RESULT: 1 offset: 4; array: no
[26301]: ecpg_get_data on line 60: RESULT: char offset: 8; array: no
[26301]: ecpg_get_data on line 60: RESULT: 08.05.1945 offset: 8; array: no
[26301]: ecpg_get_data on line 60: RESULT: освобождение offset: 81; array: no
...

What is missing are timestamps in enough precision. I will add this to
the code in postgresql-11.4/src/interfaces/ecpg/ecpglib/misc.c where the
implementation of ecpg_log() is.

Thanks

matthias

--
Matthias Apitz, ✉ guru(at)unixarea(dot)de, http://www.unixarea.de/ +49-176-38902045
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