mirror of https://github.com/postgres/postgres
Update pginterface for 6.4. add manual page.
This commit is contained in:
parent
4da5714ced
commit
a5d4642578
|
@ -16,14 +16,14 @@ have a global variable that allows you to disable the error checking I
|
||||||
have added to the doquery() routine.
|
have added to the doquery() routine.
|
||||||
|
|
||||||
I have added a function called fetch(), which allows you to pass
|
I have added a function called fetch(), which allows you to pass
|
||||||
pointers as parameters, and on return the variables are filled with the
|
pointers as parameters, and on return the variables are filled with data
|
||||||
data from the binary cursor you opened. These binary cursors are not
|
from the binary cursor you opened. These binary cursors are not useful
|
||||||
useful if you are running the query engine on a system with a different
|
if you are running the query engine on a system with a different
|
||||||
architecture than the database server. If you pass a NULL pointer, the
|
architecture than the database server. If you pass a NULL pointer, the
|
||||||
column is skipped, and you can use libpq to handle it as you wish.
|
column is skipped, and you can use libpq to handle it as you wish.
|
||||||
|
|
||||||
There are two functions, get_result() and set_result, that allow you to
|
There are two functions, get_result() and set_result(), that allow you
|
||||||
handle multiple result sets at the same time.
|
to handle multiple result sets at the same time.
|
||||||
|
|
||||||
There is a reset_fetch() that starts the fetch back at the beginning.
|
There is a reset_fetch() that starts the fetch back at the beginning.
|
||||||
|
|
||||||
|
|
|
@ -0,0 +1,71 @@
|
||||||
|
.\" This is -*-nroff-*-
|
||||||
|
.\" XXX standard disclaimer belongs here....
|
||||||
|
.\" $Header: /cvsroot/pgsql/contrib/pginterface/Attic/pginterface.3,v 1.1 1998/09/11 05:14:08 momjian Exp $
|
||||||
|
.TH PGINTERFACE INTRO 08/08/98 PostgreSQL PostgreSQL
|
||||||
|
.SH DESCRIPTION
|
||||||
|
Pginterface allows you to cleanly interface to the libpq library,
|
||||||
|
more like a 4gl SQL interface.
|
||||||
|
.PP
|
||||||
|
It consists of set of simplified C functions that encapsulate the
|
||||||
|
functionality of libpq.
|
||||||
|
The functions are:
|
||||||
|
|
||||||
|
.nf
|
||||||
|
PGresult *doquery(char *query);
|
||||||
|
PGconn *connectdb();
|
||||||
|
void disconnectdb();
|
||||||
|
|
||||||
|
int fetch(void *param,...);
|
||||||
|
int fetchwithnulls(void *param,...);
|
||||||
|
void reset_fetch();
|
||||||
|
|
||||||
|
void on_error_continue();
|
||||||
|
void on_error_stop();
|
||||||
|
|
||||||
|
PGresult *get_result();
|
||||||
|
void set_result(PGresult *newres);
|
||||||
|
void unset_result(PGresult *oldres);
|
||||||
|
.fi
|
||||||
|
.PP
|
||||||
|
Many functions return a structure or value, so you can do more work
|
||||||
|
with the result if required.
|
||||||
|
.PP
|
||||||
|
You basically connect to the database with
|
||||||
|
.BR connectdb ,
|
||||||
|
issue your query with
|
||||||
|
.BR doquery ,
|
||||||
|
fetch the results with
|
||||||
|
.BR fetch ,
|
||||||
|
and finish with
|
||||||
|
.BR disconnectdb .
|
||||||
|
.PP
|
||||||
|
For
|
||||||
|
.IR select
|
||||||
|
queries,
|
||||||
|
.BR fetch
|
||||||
|
allows you to pass pointers as parameters, and on return the variables
|
||||||
|
are filled with data from the binary cursor you opened. These binary
|
||||||
|
cursors can not be used if you are running the
|
||||||
|
.BR pginterface
|
||||||
|
client on a system with a different architecture than the database
|
||||||
|
server. If you pass a NULL pointer parameter, the column is skipped.
|
||||||
|
.BR fetchwithnulls
|
||||||
|
allows you to retieve the
|
||||||
|
.IR null
|
||||||
|
status of the field by passing an
|
||||||
|
.IR int*
|
||||||
|
after each result pointer, which returns true or false if the field is null.
|
||||||
|
You can always use libpq functions on the PGresult pointer returned by
|
||||||
|
.BR doquery .
|
||||||
|
.BR reset_fetch
|
||||||
|
starts the fetch back at the beginning.
|
||||||
|
.PP
|
||||||
|
.BR get_result ,
|
||||||
|
.BR set_result ,
|
||||||
|
and
|
||||||
|
.BR unset_result
|
||||||
|
allow you to handle multiple result sets at the same time.
|
||||||
|
.PP
|
||||||
|
There are a variety of demonstration programs in the
|
||||||
|
.BR pginterface
|
||||||
|
source directory.
|
|
@ -13,6 +13,14 @@
|
||||||
|
|
||||||
#define NUL '\0'
|
#define NUL '\0'
|
||||||
|
|
||||||
|
#ifndef TRUE
|
||||||
|
#define TRUE 1
|
||||||
|
#endif
|
||||||
|
|
||||||
|
#ifndef FALSE
|
||||||
|
#define FALSE 0
|
||||||
|
#endif
|
||||||
|
|
||||||
/* GLOBAL VARIABLES */
|
/* GLOBAL VARIABLES */
|
||||||
static PGconn *conn;
|
static PGconn *conn;
|
||||||
static PGresult *res = NULL;
|
static PGresult *res = NULL;
|
||||||
|
@ -22,8 +30,8 @@ static PGresult *res = NULL;
|
||||||
|
|
||||||
static int on_error_state = ON_ERROR_STOP;
|
static int on_error_state = ON_ERROR_STOP;
|
||||||
|
|
||||||
static in_result_block = false;
|
static in_result_block = FALSE;
|
||||||
static was_get_unset_result = false;
|
static was_get_unset_result = FALSE;
|
||||||
|
|
||||||
/* LOCAL VARIABLES */
|
/* LOCAL VARIABLES */
|
||||||
static int tuple;
|
static int tuple;
|
||||||
|
@ -67,10 +75,10 @@ disconnectdb()
|
||||||
PGresult *
|
PGresult *
|
||||||
doquery(char *query)
|
doquery(char *query)
|
||||||
{
|
{
|
||||||
if (res != NULL && in_result_block == false && was_get_unset_result == false)
|
if (res != NULL && in_result_block == FALSE && was_get_unset_result == FALSE)
|
||||||
PQclear(res);
|
PQclear(res);
|
||||||
|
|
||||||
was_get_unset_result = false;
|
was_get_unset_result = FALSE;
|
||||||
res = PQexec(conn, query);
|
res = PQexec(conn, query);
|
||||||
|
|
||||||
if (on_error_state == ON_ERROR_STOP &&
|
if (on_error_state == ON_ERROR_STOP &&
|
||||||
|
@ -131,7 +139,7 @@ fetch(void *param,...)
|
||||||
**
|
**
|
||||||
** fetchwithnulls - returns tuple number (starts at 0),
|
** fetchwithnulls - returns tuple number (starts at 0),
|
||||||
** or the value END_OF_TUPLES
|
** or the value END_OF_TUPLES
|
||||||
** Returns true or false into null indicator variables
|
** Returns TRUE or FALSE into null indicator variables
|
||||||
** NULL pointers are skipped
|
** NULL pointers are skipped
|
||||||
*/
|
*/
|
||||||
int
|
int
|
||||||
|
@ -200,9 +208,14 @@ on_error_continue()
|
||||||
*/
|
*/
|
||||||
PGresult *get_result()
|
PGresult *get_result()
|
||||||
{
|
{
|
||||||
was_get_unset_result = true;
|
char *cmdstatus = PQcmdStatus(res);
|
||||||
|
|
||||||
|
was_get_unset_result = TRUE;
|
||||||
|
|
||||||
/* we have to store the fetch location somewhere */
|
/* we have to store the fetch location somewhere */
|
||||||
memcpy(&res->cmdStatus[CMDSTATUS_LEN-sizeof(tuple)],&tuple, sizeof(tuple));
|
cmdstatus[0] = NUL;
|
||||||
|
memcpy(&cmdstatus[1],&tuple, sizeof(tuple));
|
||||||
|
|
||||||
return res;
|
return res;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
@ -213,18 +226,27 @@ PGresult *get_result()
|
||||||
*/
|
*/
|
||||||
void set_result(PGresult *newres)
|
void set_result(PGresult *newres)
|
||||||
{
|
{
|
||||||
|
|
||||||
|
char *cmdstatus = PQcmdStatus(res);
|
||||||
|
|
||||||
if (newres == NULL)
|
if (newres == NULL)
|
||||||
halt("set_result called with null result pointer\n");
|
halt("set_result called with null result pointer\n");
|
||||||
|
|
||||||
if (res != NULL && was_get_unset_result == false)
|
if (res != NULL && was_get_unset_result == FALSE)
|
||||||
if (in_result_block == false)
|
if (in_result_block == FALSE)
|
||||||
PQclear(res);
|
PQclear(res);
|
||||||
else
|
else
|
||||||
memcpy(&res->cmdStatus[CMDSTATUS_LEN-sizeof(tuple)], &tuple, sizeof(tuple));
|
{
|
||||||
|
cmdstatus[0] = NUL;
|
||||||
|
memcpy(&cmdstatus[1], &tuple, sizeof(tuple));
|
||||||
|
}
|
||||||
|
|
||||||
|
in_result_block = TRUE;
|
||||||
|
was_get_unset_result = FALSE;
|
||||||
|
|
||||||
|
cmdstatus = PQcmdStatus(newres);
|
||||||
|
memcpy(&tuple, &cmdstatus[1], sizeof(tuple));
|
||||||
|
|
||||||
in_result_block = true;
|
|
||||||
was_get_unset_result = false;
|
|
||||||
memcpy(&tuple, &newres->cmdStatus[CMDSTATUS_LEN-sizeof(tuple)], sizeof(tuple));
|
|
||||||
res = newres;
|
res = newres;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
@ -236,15 +258,18 @@ void set_result(PGresult *newres)
|
||||||
*/
|
*/
|
||||||
void unset_result(PGresult *oldres)
|
void unset_result(PGresult *oldres)
|
||||||
{
|
{
|
||||||
|
char *cmdstatus = PQcmdStatus(oldres);
|
||||||
|
|
||||||
if (oldres == NULL)
|
if (oldres == NULL)
|
||||||
halt("unset_result called with null result pointer\n");
|
halt("unset_result called with null result pointer\n");
|
||||||
|
|
||||||
if (in_result_block == false)
|
if (in_result_block == FALSE)
|
||||||
halt("Unset of result without being set.\n");
|
halt("Unset of result without being set.\n");
|
||||||
|
|
||||||
was_get_unset_result = true;
|
was_get_unset_result = TRUE;
|
||||||
memcpy(&oldres->cmdStatus[CMDSTATUS_LEN-sizeof(tuple)], &tuple, sizeof(tuple));
|
cmdstatus[0] = NUL;
|
||||||
in_result_block = false;
|
memcpy(&cmdstatus[1], &tuple, sizeof(tuple));
|
||||||
|
in_result_block = FALSE;
|
||||||
}
|
}
|
||||||
|
|
||||||
/*
|
/*
|
||||||
|
|
Loading…
Reference in New Issue