I'm trying to sipmply modify a tuple before it will be inserted in the db.
The problem is that when it try to insert the modified tuple with
SPI_modifytuple all i get is a SPI_ERROR_ARGUMENT negative (-6) .
Could someone help me? i'm reallygoing crazy.
What i did is just a fire-before C trigger that acts like this:
#include <postgres.h>
#include <executor/spi.h> /* this is what you need to work with SPI */
#include <commands/trigger.h> /* ... and triggers */
#include <string.h>
#include <utils/builtins.h>
extern Datum trgupdana(PG_FUNCTION_ARGS);
char *checkFieldData(char *);
PG_FUNCTION_INFO_V1(trgupdana);
Datum
trgupdana(PG_FUNCTION_ARGS)
{ TriggerData *trigdata = (TriggerData *) fcinfo->context; TupleDesc tupdesc; HeapTuple rettuple,
oldtuple, newtuple; char *rs1,*rs2,*rs3,*relname; int ret, i,j; bool isnull;
Relation rel;
/* make sure it's called as a trigger at all */ if (!CALLED_AS_TRIGGER(fcinfo)) elog(ERROR, "trgchkneg: not
called
by trigger manager\n");
if (TRIGGER_FIRED_BEFORE(trigdata->tg_event) &&
TRIGGER_FIRED_FOR_ROW(trigdata->tg_event)) //trigger fires when called
for rows and before updating { tupdesc = trigdata->tg_relation->rd_att; oldtuple =
trigdata->tg_trigtuple;newtuple = trigdata->tg_newtuple; rettuple=NULL;rel = trigdata->tg_relation;relname=
SPI_getrelname(rel); if ((ret = SPI_connect()) < 0) // SPI
manager initialization elog(NOTICE, "trgCheckNeg : SPI_connect returned: %d", ret);
rs1=SPI_getvalue(oldtuple,tupdesc,5); rs2=SPI_getvalue(oldtuple,tupdesc,6); elog(NOTICE,"%s,%s",rs1,rs2);
int attnum; Datum new_value; rs3=(char*) malloc(80); sprintf(rs3,"");if(rs1[strlen(rs1)-1]=='&'){
rs3=strncat(rs3,rs1,strlen(rs1)-1); rs3=strcat(rs3,"E ");} else if(rs1[strlen(rs1)-1]==','){
rs3=strncat(rs3,rs1,strlen(rs1)-1); rs3=strcat(rs3,", ");} else { rs3=rs1; }
elog(NOTICE,"1:%s",rs3); if(strlen(rs2)!=0){
rs3=strcat(rs3,rs2);}elog(NOTICE,"2:%s",rs3);new_value=DirectFunctionCall1(textin,PointerGetDatum(checkFieldData(rs3)));
attnum=SPI_fnumber(tupdesc,"ARGSL1"); if(rel==NULL) elog(NOTICE,"rel NULL");if(&attnum==NULL)
elog(NOTICE,"attnumNULL");if(&new_value==NULL) elog(NOTICE,"new_value NULL");if(&isnull==NULL) elog(NOTICE,"isnull
NULL"); rettuple=SPI_modifytuple(rel,newtuple,1,&attnum,&new_value,&isnull);if(rettuple==NULL){
elog(ERROR,"trgupdana(%s):%d returned by
SPI_modifytuple",relname,SPI_result);}return PointerGetDatum(rettuple); } return PointerGetDatum(oldtuple);
}
char *checkFieldData(char *valueToCheck){int i=0;for(i=0;i<strlen(valueToCheck);i++){ if(valueToCheck[i]=='&')
valueToCheck[i]='E'; else if(valueToCheck[i]=='\'') valueToCheck[i]=96;} return(valueToCheck);
}
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