Re: psql - add special variable to reflect the last query status

2017-06-28 10:04 GMT+02:00 Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr>:

>
> Hello Pavel,
>
> + if (success)
>> + {
>> + char *ntuples = PQcmdTuples(results);
>> + SetVariable(pset.vars, "ROW_COUNT", *ntuples ? ntuples : "0");
>> + SetVariable(pset.vars, "ERROR", "FALSE");
>> + }
>> + else
>> + {
>> + SetVariable(pset.vars, "ROW_COUNT", "0");
>> + SetVariable(pset.vars, "ERROR", "TRUE");
>> + }
>> +}
>>
>> It can be simplified
>>
>> SetVariable(pset.vars, "ROW_COUNT", success ? PQcmdTuples(results) : 0);
>>
>
> According to the documentation, PQcmdTuples returns "" in some cases and
> ISTM we want "0" instead for consistency, so that it is always a number. I
> rejected calling PQcmdTuples twice:
>
> ..., success && *PQcmdTuples(results) ? PQcmdTuples(results) : "0")
>
> Thus it makes the "if (success)" necessary for ROW_COUNT, and then it
> looked simpler to handle ERROR the same way.
>
> Now if the semantics is changed to put as row count whatever comes out of
> the function, even if not a count, then the code could indeed be simplified
> as you suggest.

Understand

Pavel

>
>
> --
> Fabien.
>