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Add PQsetdbLogin() and cleanup.

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This commit is contained in:
Bruce Momjian 1998-07-04 17:50:04 +00:00
parent 05f9966183
commit 1a2aee2d73
1 changed files with 324 additions and 233 deletions
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205
src/man/libpq.3
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@ -1,6 +1,6 @@
.\" 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
@ -654,23 +685,30 @@ exit_nicely(PGconn* conn)
main()
{
char *pghost, *pgport, *pgoptions, *pgtty;
char *pghost,
*pgport,
*pgoptions,
*pgtty;
char *dbName;
int nFields;
int i,j;
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 */
/*
* 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 */
pgoptions = NULL; /* special options to start up the backend
* server */
pgtty = NULL; /* debugging tty for the backend server */
dbName = "template1";
@ -678,7 +716,8 @@ main()
conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);
/* check to see that the backend connection was successfully made */
if (PQstatus(conn) == CONNECTION_BAD) {
if (PQstatus(conn) == CONNECTION_BAD)
{
fprintf(stderr, "Connection to database '%s' failed.\\n", dbName);
fprintf(stderr, "%s", PQerrorMessage(conn));
exit_nicely(conn);
@ -689,18 +728,26 @@ main()
/* start a transaction block */
res = PQexec(conn, "BEGIN");
if (PQresultStatus(res) != PGRES_COMMAND_OK) {
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 */
/*
* 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*/
/*
* 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) {
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
fprintf(stderr, "DECLARE CURSOR command failed\\n");
PQclear(res);
exit_nicely(conn);
@ -708,7 +755,8 @@ main()
PQclear(res);
res = PQexec(conn, "FETCH ALL in mycursor");
if (PQresultStatus(res) != PGRES_TUPLES_OK) {
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
fprintf(stderr, "FETCH ALL command didn't return tuples properly\\n");
PQclear(res);
exit_nicely(conn);
@ -716,16 +764,15 @@ main()
/* first, print out the attribute names */
nFields = PQnfields(res);
for (i=0; i < nFields; i++) {
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++) {
for (i = 0; i < PQntuples(res); i++)
{
for (j = 0; j < nFields; j++)
printf("%-15s", PQgetvalue(res, i, j));
}
printf("\\n");
}
@ -744,6 +791,7 @@ main()
/* fclose(debug); */
}
.fi
.bp
.SH "Sample Program 2"
@ -772,7 +820,8 @@ 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);
@ -780,53 +829,68 @@ void exit_nicely(PGconn* conn)
main()
{
char *pghost, *pgport, *pgoptions, *pgtty;
char *pghost,
*pgport,
*pgoptions,
*pgtty;
char *dbName;
int nFields;
int i,j;
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 */
/*
* 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 */
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*/
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) {
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) {
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 */
/*
* should PQclear PGresult whenever it is no longer needed to avoid
* memory leaks
*/
PQclear(res);
while (1) {
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) {
if (notify)
{
fprintf(stderr,
"ASYNC NOTIFY of '%s' from backend pid '%d' received\\n",
notify->relname, notify->be_pid);
@ -840,6 +904,7 @@ main()
PQfinish(conn);
}
.fi
.bp
.SH "Sample Program 3"
@ -877,7 +942,8 @@ tuple 1: got
#include "libpq-fe.h"
#include "utils/geo-decls.h" /* for the POLYGON type */
void exit_nicely(PGconn* conn)
void
exit_nicely(PGconn *conn)
{
PQfinish(conn);
exit(1);
@ -885,31 +951,42 @@ void exit_nicely(PGconn* conn)
main()
{
char *pghost, *pgport, *pgoptions, *pgtty;
char *pghost,
*pgport,
*pgoptions,
*pgtty;
char *dbName;
int nFields;
int i,j;
int i_fnum, d_fnum, p_fnum;
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 */
/*
* 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 */
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*/
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) {
if (PQstatus(conn) == CONNECTION_BAD)
{
fprintf(stderr, "Connection to database '%s' failed.\\n", dbName);
fprintf(stderr, "%s", PQerrorMessage(conn));
exit_nicely(conn);
@ -917,18 +994,26 @@ main()
/* start a transaction block */
res = PQexec(conn, "BEGIN");
if (PQresultStatus(res) != PGRES_COMMAND_OK) {
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 */
/*
* 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*/
/*
* 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) {
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
fprintf(stderr, "DECLARE CURSOR command failed\\n");
PQclear(res);
exit_nicely(conn);
@ -936,7 +1021,8 @@ main()
PQclear(res);
res = PQexec(conn, "FETCH ALL in mycursor");
if (PQresultStatus(res) != PGRES_TUPLES_OK) {
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
fprintf(stderr, "FETCH ALL command didn't return tuples properly\\n");
PQclear(res);
exit_nicely(conn);
@ -946,22 +1032,28 @@ main()
d_fnum = PQfnumber(res, "d");
p_fnum = PQfnumber(res, "p");
for (i=0;i<3;i++) {
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++) {
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*/
/*
* 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);
@ -994,4 +1086,3 @@ main()
}
.fi