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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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549
src/man/libpq.3
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@ -1,6 +1,6 @@
.\" This is -*-nroff-*- .\" This is -*-nroff-*-
.\" XXX standard disclaimer belongs here.... .\" 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 .TH LIBPQ INTRO 03/12/94 PostgreSQL PostgreSQL
.SH DESCRIPTION .SH DESCRIPTION
Libpq is the programmer's interface to Postgres. Libpq is a set of 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. from a C program.
.PP .PP
.B PQsetdb .B PQsetdb
.br
.B PQsetdbLogin
.IP .IP
Makes a new connection to a backend. 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 .nf
PGconn *PQsetdb(char *pghost, PGconn *PQsetdb(char *pghost,
char *pgport, char *pgport,
@ -118,12 +124,30 @@ PGconn *PQsetdb(char *pghost,
char *pgtty, char *pgtty,
char *dbName); char *dbName);
.fi .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 If any argument is NULL, then the corresponding environment variable
is checked. If the environment variable is also not set, then hardwired is checked. If the environment variable is also not set, then hardwired
defaults are used. defaults are used.
.IP .IP
.I PQsetdb .I PQsetdb
always returns a valid PGconn pointer. The and
.I PQsetdbLogin
always return a valid PGconn pointer. The
.I PQstatus .I PQstatus
(see below) command should be called to ensure that a connection was (see below) command should be called to ensure that a connection was
properly made before queries are sent via the connection. Libpq 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 directly referencing the fields of the PGconn structure as they are
subject to change in the future. subject to change in the future.
.IP .IP
.B PQdb .B PQdb
returns the database name of the connection. returns the database name of the connection.
.nf .nf
char *PQdb(PGconn *conn) char *PQdb(PGconn *conn)
.fi .fi
.B PQhost .B PQhost
returns the host name of the connection. returns the host name of the connection.
.nf .nf
char *PQhost(PGconn *conn) char *PQhost(PGconn *conn)
.fi .fi
.B PQoptions .B PQoptions
returns the pgoptions used in the connection. returns the pgoptions used in the connection.
.nf .nf
char *PQoptions(PGconn *conn) char *PQoptions(PGconn *conn)
.fi .fi
.B PQport .B PQport
returns the pgport of the connection. returns the pgport of the connection.
.nf .nf
char *PQport(PGconn *conn) char *PQport(PGconn *conn)
.fi .fi
.B PQtty .B PQtty
returns the pgtty of the connection. returns the pgtty of the connection.
.nf .nf
char *PQtty(PGconn *conn) char *PQtty(PGconn *conn)
.fi .fi
.B PQstatus .B PQstatus
Returns the status of the connection. The status can be CONNECTION_OK or Returns the status of the connection. The status can be CONNECTION_OK or
CONNECTION_BAD. CONNECTION_BAD.
.nf .nf
ConnStatusType *PQstatus(PGconn *conn) ConnStatusType *PQstatus(PGconn *conn)
.fi .fi
.B PQerrorMessage .B PQerrorMessage
returns the error message associated with the connection returns the error message associated with the connection
.nf .nf
@ -638,7 +669,7 @@ be silently truncated.
.nf M .nf M
/* /*
* testlibpq.c * testlibpq.c
* Test the C version of Libpq, the Postgres frontend library. * Test the C version of Libpq, the Postgres frontend library.
* *
* *
*/ */
@ -646,104 +677,121 @@ be silently truncated.
#include "libpq-fe.h" #include "libpq-fe.h"
void void
exit_nicely(PGconn* conn) exit_nicely(PGconn *conn)
{ {
PQfinish(conn); PQfinish(conn);
exit(1); exit(1);
} }
main() main()
{ {
char *pghost, *pgport, *pgoptions, *pgtty; char *pghost,
char* dbName; *pgport,
int nFields; *pgoptions,
int i,j; *pgtty;
char *dbName;
int nFields;
int i,
j;
/* FILE *debug; */ /* FILE *debug; */
PGconn* conn; PGconn *conn;
PGresult* res; PGresult *res;
/* begin, by setting the parameters for a backend connection /*
if the parameters are null, then the system will try to use * begin, by setting the parameters for a backend connection if the
reasonable defaults by looking up environment variables * parameters are null, then the system will try to use reasonable
or, failing that, using hardwired constants */ * defaults by looking up environment variables or, failing that,
pghost = NULL; /* host name of the backend server */ * using hardwired constants
pgport = NULL; /* port of the backend server */ */
pgoptions = NULL; /* special options to start up the backend server */ pghost = NULL; /* host name of the backend server */
pgtty = NULL; /* debugging tty for the backend server */ pgport = NULL; /* port of the backend server */
dbName = "template1"; 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 */ /* make a connection to the database */
conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName); conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);
/* check to see that the backend connection was successfully made */ /* 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)); fprintf(stderr, "Connection to database '%s' failed.\\n", dbName);
exit_nicely(conn); fprintf(stderr, "%s", PQerrorMessage(conn));
} exit_nicely(conn);
}
/* debug = fopen("/tmp/trace.out","w"); */ /* debug = fopen("/tmp/trace.out","w"); */
/* PQtrace(conn, debug); */ /* PQtrace(conn, debug); */
/* start a transaction block */ /* start a transaction block */
res = PQexec(conn,"BEGIN"); res = PQexec(conn, "BEGIN");
if (PQresultStatus(res) != PGRES_COMMAND_OK) { if (PQresultStatus(res) != PGRES_COMMAND_OK)
fprintf(stderr,"BEGIN command failed\\n"); {
PQclear(res); fprintf(stderr, "BEGIN command failed\\n");
exit_nicely(conn); 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");
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");
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));
} }
printf("\\n");
}
PQclear(res); /*
* should PQclear PGresult whenever it is no longer needed to avoid
* memory leaks
*/
PQclear(res);
/* close the cursor */ /*
res = PQexec(conn, "CLOSE mycursor"); * fetch instances from the pg_database, the system catalog of
PQclear(res); * 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);
/* commit the transaction */ res = PQexec(conn, "FETCH ALL in mycursor");
res = PQexec(conn, "COMMIT"); if (PQresultStatus(res) != PGRES_TUPLES_OK)
PQclear(res); {
fprintf(stderr, "FETCH ALL command didn't return tuples properly\\n");
PQclear(res);
exit_nicely(conn);
}
/* close the connection to the database and cleanup */ /* first, print out the attribute names */
PQfinish(conn); 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");
}
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);
/* fclose(debug); */ /* fclose(debug); */
} }
.fi .fi
.bp .bp
.SH "Sample Program 2" .SH "Sample Program 2"
@ -751,7 +799,7 @@ main()
.nf M .nf M
/* /*
* testlibpq2.c * testlibpq2.c
* Test of the asynchronous notification interface * Test of the asynchronous notification interface
* *
populate a database with the following: populate a database with the following:
@ -772,74 +820,91 @@ INSERT INTO TBL1 values (10);
#include <stdio.h> #include <stdio.h>
#include "libpq-fe.h" #include "libpq-fe.h"
void exit_nicely(PGconn* conn) void
exit_nicely(PGconn *conn)
{ {
PQfinish(conn); PQfinish(conn);
exit(1); exit(1);
} }
main() main()
{ {
char *pghost, *pgport, *pgoptions, *pgtty; char *pghost,
char* dbName; *pgport,
int nFields; *pgoptions,
int i,j; *pgtty;
char *dbName;
int nFields;
int i,
j;
PGconn* conn; PGconn *conn;
PGresult* res; PGresult *res;
PGnotify* notify; PGnotify *notify;
/* begin, by setting the parameters for a backend connection /*
if the parameters are null, then the system will try to use * begin, by setting the parameters for a backend connection if the
reasonable defaults by looking up environment variables * parameters are null, then the system will try to use reasonable
or, failing that, using hardwired constants */ * defaults by looking up environment variables or, failing that,
pghost = NULL; /* host name of the backend server */ * using hardwired constants
pgport = NULL; /* port of the backend server */ */
pgoptions = NULL; /* special options to start up the backend server */ pghost = NULL; /* host name of the backend server */
pgtty = NULL; /* debugging tty for the backend server */ pgport = NULL; /* port of the backend server */
dbName = getenv("USER"); /* change this to the name of your test database*/ 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 */ /* make a connection to the database */
conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName); conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);
/* check to see that the backend connection was successfully made */ /* 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)); fprintf(stderr, "Connection to database '%s' failed.\\n", dbName);
exit_nicely(conn); fprintf(stderr, "%s", PQerrorMessage(conn));
} exit_nicely(conn);
}
res = PQexec(conn, "LISTEN TBL2"); res = PQexec(conn, "LISTEN TBL2");
if (PQresultStatus(res) != PGRES_COMMAND_OK) { if (PQresultStatus(res) != PGRES_COMMAND_OK)
fprintf(stderr,"LISTEN command failed\\n"); {
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); PQclear(res);
exit_nicely(conn);
}
/* 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 */ /* async notification only come back as a result of a query */
res = PQexec(conn, ""); /* we can send empty queries */
res = PQexec(conn, "");
/* printf("res->status = %s\\n", pgresStatus[PQresultStatus(res)]); */ /* printf("res->status = %s\\n", pgresStatus[PQresultStatus(res)]); */
/* check for asynchronous returns */ /* check for asynchronous returns */
notify = PQnotifies(conn); notify = PQnotifies(conn);
if (notify) { if (notify)
fprintf(stderr, {
"ASYNC NOTIFY of '%s' from backend pid '%d' received\\n", fprintf(stderr,
notify->relname, notify->be_pid); "ASYNC NOTIFY of '%s' from backend pid '%d' received\\n",
free(notify); notify->relname, notify->be_pid);
break; free(notify);
} break;
PQclear(res); }
} PQclear(res);
}
/* close the connection to the database and cleanup */ /* close the connection to the database and cleanup */
PQfinish(conn); PQfinish(conn);
} }
.fi .fi
.bp .bp
.SH "Sample Program 3" .SH "Sample Program 3"
@ -847,7 +912,7 @@ main()
.nf M .nf M
/* /*
* testlibpq3.c * 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 * tests the binary cursor interface
* *
* *
@ -875,123 +940,149 @@ tuple 1: got
*/ */
#include <stdio.h> #include <stdio.h>
#include "libpq-fe.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); PQfinish(conn);
exit(1); exit(1);
} }
main() main()
{ {
char *pghost, *pgport, *pgoptions, *pgtty; char *pghost,
char* dbName; *pgport,
int nFields; *pgoptions,
int i,j; *pgtty;
int i_fnum, d_fnum, p_fnum; char *dbName;
int nFields;
int i,
j;
int i_fnum,
d_fnum,
p_fnum;
PGconn* conn; PGconn *conn;
PGresult* res; PGresult *res;
/* begin, by setting the parameters for a backend connection /*
if the parameters are null, then the system will try to use * begin, by setting the parameters for a backend connection if the
reasonable defaults by looking up environment variables * parameters are null, then the system will try to use reasonable
or, failing that, using hardwired constants */ * defaults by looking up environment variables or, failing that,
pghost = NULL; /* host name of the backend server */ * using hardwired constants
pgport = NULL; /* port of the backend server */ */
pgoptions = NULL; /* special options to start up the backend server */ pghost = NULL; /* host name of the backend server */
pgtty = NULL; /* debugging tty for 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*/ dbName = getenv("USER"); /* change this to the name of your test
* database */
/* make a connection to the database */ /* make a connection to the database */
conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName); conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);
/* check to see that the backend connection was successfully made */ /* 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)); fprintf(stderr, "Connection to database '%s' failed.\\n", dbName);
exit_nicely(conn); fprintf(stderr, "%s", PQerrorMessage(conn));
} exit_nicely(conn);
}
/* start a transaction block */ /* start a transaction block */
res = PQexec(conn,"BEGIN"); res = PQexec(conn, "BEGIN");
if (PQresultStatus(res) != PGRES_COMMAND_OK) { if (PQresultStatus(res) != PGRES_COMMAND_OK)
fprintf(stderr,"BEGIN command failed\\n"); {
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); 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"); * fetch instances from the pg_database, the system catalog of
if (PQresultStatus(res) != PGRES_COMMAND_OK) { * databases
fprintf(stderr,"DECLARE CURSOR command failed\\n"); */
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); PQclear(res);
exit_nicely(conn);
}
PQclear(res);
res = PQexec(conn,"FETCH ALL in mycursor"); 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"); {
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); PQclear(res);
exit_nicely(conn);
}
i_fnum = PQfnumber(res,"i"); /* close the cursor */
d_fnum = PQfnumber(res,"d"); res = PQexec(conn, "CLOSE mycursor");
p_fnum = PQfnumber(res,"p"); PQclear(res);
for (i=0;i<3;i++) { /* commit the transaction */
printf("type[%d] = %d, size[%d] = %d\\n", res = PQexec(conn, "COMMIT");
i, PQftype(res,i), PQclear(res);
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*/ /* close the connection to the database and cleanup */
pval = (POLYGON*) malloc(plen + VARHDRSZ); PQfinish(conn);
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);
} }
.fi .fi