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Postgres FD Implementation
Commit 1a2aee2d authored by Bruce Momjian's avatar Bruce Momjian
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Add PQsetdbLogin() and cleanup.

parent 05f99661
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src/man/libpq.3
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.\" This is -*-nroff-*-
.\" XXX standard disclaimer belongs here....
.\" $Header: /cvsroot/pgsql/src/man/Attic/libpq.3,v 1.17 1998/06/24 13:21:27 momjian Exp $
.\" $Header: /cvsroot/pgsql/src/man/Attic/libpq.3,v 1.18 1998/07/04 17:50:04 momjian Exp $
.TH LIBPQ INTRO 03/12/94 PostgreSQL PostgreSQL
.SH DESCRIPTION
Libpq is the programmer's interface to Postgres. Libpq is a set of
......@@ -109,8 +109,14 @@ The following routines deal with making a connection to a backend
from a C program.
.PP
.B PQsetdb
.br
.B PQsetdbLogin
.IP
Makes a new connection to a backend.
.B PQsetdb
is the method usually used to
connect to the database when username/password authentication is not
needed.
.nf
PGconn *PQsetdb(char *pghost,
char *pgport,
......@@ -118,12 +124,30 @@ PGconn *PQsetdb(char *pghost,
char *pgtty,
char *dbName);
.fi
.IP
.B PQsetdbLogin
is the method used to
connect to the database when username/password authentication is
needed.
.nf
PGconn *PQsetdbLogin(char *pghost,
char *pgport,
char *pgoptions,
char *pgtty,
char *dbName,
char *login,
char *pwd);
.fi
If any argument is NULL, then the corresponding environment variable
is checked. If the environment variable is also not set, then hardwired
defaults are used.
.IP
.I PQsetdb
always returns a valid PGconn pointer. The
and
.I PQsetdbLogin
always return a valid PGconn pointer. The
.I PQstatus
(see below) command should be called to ensure that a connection was
properly made before queries are sent via the connection. Libpq
......@@ -132,37 +156,44 @@ the accessor functions below to get at the contents of PGconn. Avoid
directly referencing the fields of the PGconn structure as they are
subject to change in the future.
.IP
.B PQdb
returns the database name of the connection.
.nf
char *PQdb(PGconn *conn)
.fi
.B PQhost
returns the host name of the connection.
.nf
char *PQhost(PGconn *conn)
.fi
.B PQoptions
returns the pgoptions used in the connection.
.nf
char *PQoptions(PGconn *conn)
.fi
.B PQport
returns the pgport of the connection.
.nf
char *PQport(PGconn *conn)
.fi
.B PQtty
returns the pgtty of the connection.
.nf
char *PQtty(PGconn *conn)
.fi
.B PQstatus
Returns the status of the connection. The status can be CONNECTION_OK or
CONNECTION_BAD.
.nf
ConnStatusType *PQstatus(PGconn *conn)
.fi
.B PQerrorMessage
returns the error message associated with the connection
.nf
......@@ -638,112 +669,129 @@ be silently truncated.
.nf M
/*
* testlibpq.c
* Test the C version of Libpq, the Postgres frontend library.
* Test the C version of Libpq, the Postgres frontend library.
*
*
*/
#include <stdio.h>
#include "libpq-fe.h"
void
exit_nicely(PGconn* conn)
void
exit_nicely(PGconn *conn)
{
PQfinish(conn);
exit(1);
PQfinish(conn);
exit(1);
}
main()
{
char *pghost, *pgport, *pgoptions, *pgtty;
char* dbName;
int nFields;
int i,j;
char *pghost,
*pgport,
*pgoptions,
*pgtty;
char *dbName;
int nFields;
int i,
j;
/* FILE *debug; */
PGconn* conn;
PGresult* res;
/* begin, by setting the parameters for a backend connection
if the parameters are null, then the system will try to use
reasonable defaults by looking up environment variables
or, failing that, using hardwired constants */
pghost = NULL; /* host name of the backend server */
pgport = NULL; /* port of the backend server */
pgoptions = NULL; /* special options to start up the backend server */
pgtty = NULL; /* debugging tty for the backend server */
dbName = "template1";
/* make a connection to the database */
conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);
/* check to see that the backend connection was successfully made */
if (PQstatus(conn) == CONNECTION_BAD) {
fprintf(stderr,"Connection to database '%s' failed.\\n", dbName);
fprintf(stderr,"%s",PQerrorMessage(conn));
exit_nicely(conn);
}
PGconn *conn;
PGresult *res;
/*
* begin, by setting the parameters for a backend connection if the
* parameters are null, then the system will try to use reasonable
* defaults by looking up environment variables or, failing that,
* using hardwired constants
*/
pghost = NULL; /* host name of the backend server */
pgport = NULL; /* port of the backend server */
pgoptions = NULL; /* special options to start up the backend
* server */
pgtty = NULL; /* debugging tty for the backend server */
dbName = "template1";
/* make a connection to the database */
conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);
/* check to see that the backend connection was successfully made */
if (PQstatus(conn) == CONNECTION_BAD)
{
fprintf(stderr, "Connection to database '%s' failed.\\n", dbName);
fprintf(stderr, "%s", PQerrorMessage(conn));
exit_nicely(conn);
}
/* debug = fopen("/tmp/trace.out","w"); */
/* PQtrace(conn, debug); */
/* start a transaction block */
res = PQexec(conn,"BEGIN");
if (PQresultStatus(res) != PGRES_COMMAND_OK) {
fprintf(stderr,"BEGIN command failed\\n");
PQclear(res);
exit_nicely(conn);
}
/* should PQclear PGresult whenever it is no longer needed to avoid
memory leaks */
PQclear(res);
/* fetch instances from the pg_database, the system catalog of databases*/
res = PQexec(conn,"DECLARE mycursor CURSOR FOR select * from pg_database");
if (PQresultStatus(res) != PGRES_COMMAND_OK) {
fprintf(stderr,"DECLARE CURSOR command failed\\n");
/* start a transaction block */
res = PQexec(conn, "BEGIN");
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
fprintf(stderr, "BEGIN command failed\\n");
PQclear(res);
exit_nicely(conn);
}
/*
* should PQclear PGresult whenever it is no longer needed to avoid
* memory leaks
*/
PQclear(res);
exit_nicely(conn);
}
PQclear(res);
res = PQexec(conn,"FETCH ALL in mycursor");
if (PQresultStatus(res) != PGRES_TUPLES_OK) {
fprintf(stderr,"FETCH ALL command didn't return tuples properly\\n");
/*
* fetch instances from the pg_database, the system catalog of
* databases
*/
res = PQexec(conn, "DECLARE mycursor CURSOR FOR select * from pg_database");
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
fprintf(stderr, "DECLARE CURSOR command failed\\n");
PQclear(res);
exit_nicely(conn);
}
PQclear(res);
exit_nicely(conn);
}
/* first, print out the attribute names */
nFields = PQnfields(res);
for (i=0; i < nFields; i++) {
printf("%-15s",PQfname(res,i));
}
printf("\\n\\n");
/* next, print out the instances */
for (i=0; i < PQntuples(res); i++) {
for (j=0 ; j < nFields; j++) {
printf("%-15s", PQgetvalue(res,i,j));
res = PQexec(conn, "FETCH ALL in mycursor");
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
fprintf(stderr, "FETCH ALL command didn't return tuples properly\\n");
PQclear(res);
exit_nicely(conn);
}
printf("\\n");
}
PQclear(res);
/* close the cursor */
res = PQexec(conn, "CLOSE mycursor");
PQclear(res);
/* first, print out the attribute names */
nFields = PQnfields(res);
for (i = 0; i < nFields; i++)
printf("%-15s", PQfname(res, i));
printf("\\n\\n");
/* next, print out the instances */
for (i = 0; i < PQntuples(res); i++)
{
for (j = 0; j < nFields; j++)
printf("%-15s", PQgetvalue(res, i, j));
printf("\\n");
}
/* commit the transaction */
res = PQexec(conn, "COMMIT");
PQclear(res);
PQclear(res);
/* close the cursor */
res = PQexec(conn, "CLOSE mycursor");
PQclear(res);
/* close the connection to the database and cleanup */
PQfinish(conn);
/* commit the transaction */
res = PQexec(conn, "COMMIT");
PQclear(res);
/* close the connection to the database and cleanup */
PQfinish(conn);
/* fclose(debug); */
}
.fi
.bp
.SH "Sample Program 2"
......@@ -751,7 +799,7 @@ main()
.nf M
/*
* testlibpq2.c
* Test of the asynchronous notification interface
* Test of the asynchronous notification interface
*
populate a database with the following:
......@@ -772,74 +820,91 @@ INSERT INTO TBL1 values (10);
#include <stdio.h>
#include "libpq-fe.h"
void exit_nicely(PGconn* conn)
void
exit_nicely(PGconn *conn)
{
PQfinish(conn);
exit(1);
PQfinish(conn);
exit(1);
}
main()
{
char *pghost, *pgport, *pgoptions, *pgtty;
char* dbName;
int nFields;
int i,j;
PGconn* conn;
PGresult* res;
PGnotify* notify;
/* begin, by setting the parameters for a backend connection
if the parameters are null, then the system will try to use
reasonable defaults by looking up environment variables
or, failing that, using hardwired constants */
pghost = NULL; /* host name of the backend server */
pgport = NULL; /* port of the backend server */
pgoptions = NULL; /* special options to start up the backend server */
pgtty = NULL; /* debugging tty for the backend server */
dbName = getenv("USER"); /* change this to the name of your test database*/
/* make a connection to the database */
conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);
/* check to see that the backend connection was successfully made */
if (PQstatus(conn) == CONNECTION_BAD) {
fprintf(stderr,"Connection to database '%s' failed.\\n", dbName);
fprintf(stderr,"%s",PQerrorMessage(conn));
exit_nicely(conn);
}
res = PQexec(conn, "LISTEN TBL2");
if (PQresultStatus(res) != PGRES_COMMAND_OK) {
fprintf(stderr,"LISTEN command failed\\n");
char *pghost,
*pgport,
*pgoptions,
*pgtty;
char *dbName;
int nFields;
int i,
j;
PGconn *conn;
PGresult *res;
PGnotify *notify;
/*
* begin, by setting the parameters for a backend connection if the
* parameters are null, then the system will try to use reasonable
* defaults by looking up environment variables or, failing that,
* using hardwired constants
*/
pghost = NULL; /* host name of the backend server */
pgport = NULL; /* port of the backend server */
pgoptions = NULL; /* special options to start up the backend
* server */
pgtty = NULL; /* debugging tty for the backend server */
dbName = getenv("USER"); /* change this to the name of your test
* database */
/* make a connection to the database */
conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);
/* check to see that the backend connection was successfully made */
if (PQstatus(conn) == CONNECTION_BAD)
{
fprintf(stderr, "Connection to database '%s' failed.\\n", dbName);
fprintf(stderr, "%s", PQerrorMessage(conn));
exit_nicely(conn);
}
res = PQexec(conn, "LISTEN TBL2");
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
fprintf(stderr, "LISTEN command failed\\n");
PQclear(res);
exit_nicely(conn);
}
/*
* should PQclear PGresult whenever it is no longer needed to avoid
* memory leaks
*/
PQclear(res);
exit_nicely(conn);
}
/* should PQclear PGresult whenever it is no longer needed to avoid
memory leaks */
PQclear(res);
while (1) {
/* async notification only come back as a result of a query*/
/* we can send empty queries */
res = PQexec(conn, "");
while (1)
{
/* async notification only come back as a result of a query */
/* we can send empty queries */
res = PQexec(conn, "");
/* printf("res->status = %s\\n", pgresStatus[PQresultStatus(res)]); */
/* check for asynchronous returns */
notify = PQnotifies(conn);
if (notify) {
fprintf(stderr,
"ASYNC NOTIFY of '%s' from backend pid '%d' received\\n",
notify->relname, notify->be_pid);
free(notify);
break;
}
PQclear(res);
}
/* close the connection to the database and cleanup */
PQfinish(conn);
/* check for asynchronous returns */
notify = PQnotifies(conn);
if (notify)
{
fprintf(stderr,
"ASYNC NOTIFY of '%s' from backend pid '%d' received\\n",
notify->relname, notify->be_pid);
free(notify);
break;
}
PQclear(res);
}
/* close the connection to the database and cleanup */
PQfinish(conn);
}
.fi
.bp
.SH "Sample Program 3"
......@@ -847,13 +912,13 @@ main()
.nf M
/*
* testlibpq3.c
* Test the C version of Libpq, the Postgres frontend library.
* 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);
......@@ -875,123 +940,149 @@ tuple 1: got
*/
#include <stdio.h>
#include "libpq-fe.h"
#include "utils/geo-decls.h" /* for the POLYGON type */
#include "utils/geo-decls.h" /* for the POLYGON type */
void exit_nicely(PGconn* conn)
void
exit_nicely(PGconn *conn)
{
PQfinish(conn);
exit(1);
PQfinish(conn);
exit(1);
}
main()
{
char *pghost, *pgport, *pgoptions, *pgtty;
char* dbName;
int nFields;
int i,j;
int i_fnum, d_fnum, p_fnum;
PGconn* conn;
PGresult* res;
/* begin, by setting the parameters for a backend connection
if the parameters are null, then the system will try to use
reasonable defaults by looking up environment variables
or, failing that, using hardwired constants */
pghost = NULL; /* host name of the backend server */
pgport = NULL; /* port of the backend server */
pgoptions = NULL; /* special options to start up the backend server */
pgtty = NULL; /* debugging tty for the backend server */
dbName = getenv("USER"); /* change this to the name of your test database*/
/* make a connection to the database */
conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);
/* check to see that the backend connection was successfully made */
if (PQstatus(conn) == CONNECTION_BAD) {
fprintf(stderr,"Connection to database '%s' failed.\\n", dbName);
fprintf(stderr,"%s",PQerrorMessage(conn));
exit_nicely(conn);
}
/* start a transaction block */
res = PQexec(conn,"BEGIN");
if (PQresultStatus(res) != PGRES_COMMAND_OK) {
fprintf(stderr,"BEGIN command failed\\n");
char *pghost,
*pgport,
*pgoptions,
*pgtty;
char *dbName;
int nFields;
int i,
j;
int i_fnum,
d_fnum,
p_fnum;
PGconn *conn;
PGresult *res;
/*
* begin, by setting the parameters for a backend connection if the
* parameters are null, then the system will try to use reasonable
* defaults by looking up environment variables or, failing that,
* using hardwired constants
*/
pghost = NULL; /* host name of the backend server */
pgport = NULL; /* port of the backend server */
pgoptions = NULL; /* special options to start up the backend
* server */
pgtty = NULL; /* debugging tty for the backend server */
dbName = getenv("USER"); /* change this to the name of your test
* database */
/* make a connection to the database */
conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);
/* check to see that the backend connection was successfully made */
if (PQstatus(conn) == CONNECTION_BAD)
{
fprintf(stderr, "Connection to database '%s' failed.\\n", dbName);
fprintf(stderr, "%s", PQerrorMessage(conn));
exit_nicely(conn);
}
/* start a transaction block */
res = PQexec(conn, "BEGIN");
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
fprintf(stderr, "BEGIN command failed\\n");
PQclear(res);
exit_nicely(conn);
}
/*
* should PQclear PGresult whenever it is no longer needed to avoid
* memory leaks
*/
PQclear(res);
exit_nicely(conn);
}
/* should PQclear PGresult whenever it is no longer needed to avoid
memory leaks */
PQclear(res);
/* fetch instances from the pg_database, the system catalog of databases*/
res = PQexec(conn,"DECLARE mycursor BINARY CURSOR FOR select * from test1");
if (PQresultStatus(res) != PGRES_COMMAND_OK) {
fprintf(stderr,"DECLARE CURSOR command failed\\n");
/*
* fetch instances from the pg_database, the system catalog of
* databases
*/
res = PQexec(conn, "DECLARE mycursor BINARY CURSOR FOR select * from test1");
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
fprintf(stderr, "DECLARE CURSOR command failed\\n");
PQclear(res);
exit_nicely(conn);
}
PQclear(res);
exit_nicely(conn);
}
PQclear(res);
res = PQexec(conn,"FETCH ALL in mycursor");
if (PQresultStatus(res) != PGRES_TUPLES_OK) {
fprintf(stderr,"FETCH ALL command didn't return tuples properly\\n");
res = PQexec(conn, "FETCH ALL in mycursor");
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
fprintf(stderr, "FETCH ALL command didn't return tuples properly\\n");
PQclear(res);
exit_nicely(conn);
}
i_fnum = PQfnumber(res, "i");
d_fnum = PQfnumber(res, "d");
p_fnum = PQfnumber(res, "p");
for (i = 0; i < 3; i++)
{
printf("type[%d] = %d, size[%d] = %d\\n",
i, PQftype(res, i),
i, PQfsize(res, i));
}
for (i = 0; i < PQntuples(res); i++)
{
int *ival;
float *dval;
int plen;
POLYGON *pval;
/* we hard-wire this to the 3 fields we know about */
ival = (int *) PQgetvalue(res, i, i_fnum);
dval = (float *) PQgetvalue(res, i, d_fnum);
plen = PQgetlength(res, 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, PQgetvalue(res, i, p_fnum), plen);
printf("tuple %d: got\\n", i);
printf(" i = (%d bytes) %d,\\n",
PQgetlength(res, i, i_fnum), *ival);
printf(" d = (%d bytes) %f,\\n",
PQgetlength(res, i, d_fnum), *dval);
printf(" p = (%d bytes) %d points \\tboundbox = (hi=%f/%f, lo = %f,%f)\\n",
PQgetlength(res, i, d_fnum),
pval->npts,
pval->boundbox.xh,
pval->boundbox.yh,
pval->boundbox.xl,
pval->boundbox.yl);
}
PQclear(res);
exit_nicely(conn);
}
i_fnum = PQfnumber(res,"i");
d_fnum = PQfnumber(res,"d");
p_fnum = PQfnumber(res,"p");
for (i=0;i<3;i++) {
printf("type[%d] = %d, size[%d] = %d\\n",
i, PQftype(res,i),
i, PQfsize(res,i));
}
for (i=0; i < PQntuples(res); i++) {
int *ival;
float *dval;
int plen;
POLYGON* pval;
/* we hard-wire this to the 3 fields we know about */
ival = (int*)PQgetvalue(res,i,i_fnum);
dval = (float*)PQgetvalue(res,i,d_fnum);
plen = PQgetlength(res,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, PQgetvalue(res,i,p_fnum), plen);
printf("tuple %d: got\\n", i);
printf(" i = (%d bytes) %d,\\n",
PQgetlength(res,i,i_fnum), *ival);
printf(" d = (%d bytes) %f,\\n",
PQgetlength(res,i,d_fnum), *dval);
printf(" p = (%d bytes) %d points \\tboundbox = (hi=%f/%f, lo = %f,%f)\\n",
PQgetlength(res,i,d_fnum),
pval->npts,
pval->boundbox.xh,
pval->boundbox.yh,
pval->boundbox.xl,
pval->boundbox.yl);
}
PQclear(res);
/* close the cursor */
res = PQexec(conn, "CLOSE mycursor");
PQclear(res);
/* commit the transaction */
res = PQexec(conn, "COMMIT");
PQclear(res);
/* close the connection to the database and cleanup */
PQfinish(conn);
/* close the cursor */
res = PQexec(conn, "CLOSE mycursor");
PQclear(res);
/* commit the transaction */
res = PQexec(conn, "COMMIT");
PQclear(res);
/* close the connection to the database and cleanup */
PQfinish(conn);
}
.fi
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