Hello all,I am having a problem accessing variable length
arrays ( or rather fields ) in postgres tables from
a C program. Can somebody please help me out ?
I've included the source files below. I've have not included
the error checks (CONNECTION_BAD etc).Thanks in advance, -npd
file test.sql
---------------
create table temp (key int4, count int4, a int4[], b int4[]);
insert into temp values( 1, 2, '{1,2}', '{3,4}' );
insert into temp values( 2, 1, '{1}', '{2}' );
insert into temp values( 3, 3, '{1,2,3}', '{3,4,5}' );
file test.c
-------------
include <stdio.h>
#include <pgsql/libpq-fe.h>
main()
{PGconn *conn;PGresult *res;int nf;int i, j, k;
conn = PQsetdb(NULL,NULL,NULL,NULL,"test");res = PQexec(conn,"BEGIN");PQclear(res);res = PQexec(conn,"DECLARE mc BINARY
CURSORFOR select * from temp");PQclear(res);res = PQexec(conn,"FETCH ALL in mc");PQclear(res);
nf = PQnfields(res);
for(i=0;i<PQntuples(res);++i){ int *key, *count; int *a, *b, la, lb; key = PQgetvalue(res,i,0); count =
PQgetvalue(res,i,1); la = PQgetlength(res,i,2); lb = PQgetlength(res,i,3); a = (int *) malloc(la); b = (int
*)malloc(lb); memmove(a,PQgetvalue(res,i,3),la); printf("i = %d key = %d c = %d",i,*key,*count);
for(j=0;j<*count;++j) { printf(" elem a[%d] = %d, b[%d]",j,a[j],j,b[j]); } printf("\n");}
PQclear(res);res = PQexec(conn,"CLOSE mc"); PQclear(res);res = PQexec(conn,"COMMIT"); PQclear(res);PQfinish(conn);
}
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