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/*
* testlibpq3.cc
* Test the C++ version of LIBPQ, the POSTGRES frontend library.
* tests the binary cursor interface
*
*
*
populate a database by doing the following:
CREATE TABLE test1 (i int4, d float4, p polygon);
INSERT INTO test1 values (1, 3.567, '(3.0, 4.0, 1.0, 2.0)'::polygon);
INSERT INTO test1 values (2, 89.05, '(4.0, 3.0, 2.0, 1.0)'::polygon);
the expected output is:
tuple 0: got
i = (4 bytes) 1,
d = (4 bytes) 3.567000,
p = (4 bytes) 2 points boundbox = (hi=3.000000/4.000000, lo = 1.000000,2.000000)
tuple 1: got
i = (4 bytes) 2,
d = (4 bytes) 89.050003,
p = (4 bytes) 2 points boundbox = (hi=4.000000/3.000000, lo = 2.000000,1.000000)
*
*/
#include <stdio.h>
#include "libpq++.H"
extern "C" {
#include "utils/geo-decls.h" /* for the POLYGON type */
}
main()
{
char* dbName;
int nFields;
int i,j;
int i_fnum, d_fnum, p_fnum;
/* begin, by creating the parameter environtment for a backend
connection. When no parameters are given then the system will
try to use reasonable defaults by looking up environment variables
or, failing that, using hardwired constants */
PGenv env;
PGdatabase* data;
dbName = getenv("USER"); /* change this to the name of your test database */
/* make a connection to the database */
data = new PGdatabase(&env, dbName);
/* check to see that the backend connection was successfully made */
if (data->status() == CONNECTION_BAD) {
fprintf(stderr,"Connection to database '%s' failed.\n", dbName);
fprintf(stderr,"%s",data->errormessage());
delete data;
exit(1);
}
/* start a transaction block */
if (data->exec("BEGIN") != PGRES_COMMAND_OK) {
fprintf(stderr,"BEGIN command failed\n");
delete data;
exit(1);
}
/* fetch instances from the pg_database, the system catalog of databases*/
if (data->exec("DECLARE mycursor BINARY CURSOR FOR select * from test1")
!= PGRES_COMMAND_OK) {
fprintf(stderr,"DECLARE CURSOR command failed\n");
delete data;
exit(1);
}
if (data->exec("FETCH ALL in mycursor") != PGRES_TUPLES_OK) {
fprintf(stderr,"FETCH ALL command didn't return tuples properly\n");
delete data;
exit(1);
}
i_fnum = data->fieldnum("i");
d_fnum = data->fieldnum("d");
p_fnum = data->fieldnum("p");
/*
for (i=0;i<3;i++) {
printf("type[%d] = %d, size[%d] = %d\n",
i, data->fieldtype(i),
i, data->fieldsize(i));
}
*/
for (i=0; i < data->ntuples(); i++) {
int *ival;
float *dval;
int plen;
POLYGON* pval;
/* we hard-wire this to the 3 fields we know about */
ival = (int*)data->getvalue(i,i_fnum);
dval = (float*)data->getvalue(i,d_fnum);
plen = data->getlength(i,p_fnum);
/* plen doesn't include the length field so need to increment by VARHDSZ*/
pval = (POLYGON*) malloc(plen + VARHDRSZ);
pval->size = plen;
memmove((char*)&pval->npts, data->getvalue(i,p_fnum), plen);
printf("tuple %d: got\n", i);
printf(" i = (%d bytes) %d,\n",
data->getlength(i,i_fnum), *ival);
printf(" d = (%d bytes) %f,\n",
data->getlength(i,d_fnum), *dval);
printf(" p = (%d bytes) %d points \tboundbox = (hi=%f/%f, lo = %f,%f)\n",
data->getlength(i,d_fnum),
pval->npts,
pval->boundbox.xh,
pval->boundbox.yh,
pval->boundbox.xl,
pval->boundbox.yl);
}
/* close the portal */
data->exec("CLOSE mycursor");
/* end the transaction */
data->exec("END");
/* close the connection to the database and cleanup */
delete data;
}
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