[HACKERS] return a set of records

[Werner Echezuria]

Hi, I need to return a set of records from a query, first I translate
from sqlf to sql and later I wanna return the query, but the server
crash (I guess it crashes around the yyparse call).

This is the sql:

CREATE OR REPLACE FUNCTION sqlf (text) RETURNS SETOF record
AS 'MODULE_PATHNAME', 'sqlf'
LANGUAGE C IMMUTABLE STRICT;

This is the function:

Datum sqlf(PG_FUNCTION_ARGS) {

    char *query = TextDatumGetCString(PG_GETARG_DATUM(0));
    void *result;
    int               ret,proc;
    int j,i;

    FuncCallContext *funcctx;
    int call_cntr;
    int max_calls;

    TupleDesc tupdesc;
    SPITupleTable *tuptable;
    AttInMetadata *attinmeta;

    yy_scan_string(query);
    sqlf_yyparse(&result);

     // stuff done only on the first call of the function

    if (SRF_IS_FIRSTCALL()) {

        MemoryContext oldcontext;

        // create a function context for cross-call persistence
        funcctx = SRF_FIRSTCALL_INIT();

        // switch to memory context appropriate for multiple
        // function calls

        oldcontext =MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);

        SPI_connect();
        ret=SPI_execute(result,true,0);
        proc=SPI_processed;

        // total number of tuples to be returned
        funcctx->max_calls = proc;

        if (ret > 0 && SPI_tuptable != NULL){
            tupdesc = SPI_tuptable->tupdesc;
            tuptable = SPI_tuptable;
        }

         MemoryContextSwitchTo(oldcontext);
    }

    // stuff done on every call of the function

    funcctx = SRF_PERCALL_SETUP();

    call_cntr = funcctx->call_cntr;
    max_calls = funcctx->max_calls;
    attinmeta = funcctx->attinmeta;

    j=0;
    if (call_cntr < max_calls) { // do when there is more left to send
        Datum *values;
        HeapTuple tuple;
        Datum datum_result;
        bool isnull;

        values = (Datum **) palloc(tupdesc->natts * sizeof(Datum *));

        for (i = 1; i <= tupdesc->natts; i++)
            values[i]=SPI_getbinval(tuple,tupdesc,i,&isnull);

        tuple=tuptable->vals[j];

        // make the tuple into a datum
        datum_result = HeapTupleGetDatum(tuple);

        j++;

        SRF_RETURN_NEXT(funcctx, datum_result);

    } else { // do when there is no more left

        SRF_RETURN_DONE(funcctx);
    }

}

Greetings.

-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers