PQparamCreate(3) libpqtypes Manual PQparamCreate(3)NAME
PQparamCreate, PQparamCount PQparamReset, PQparamClear - PGparam man‐
agement functions.
SYNOPSIS
#include <libpqtypes.h>
PGparam *PQparamCreate(const PGconn *conn);
PGparam *PQparamDup(PGparam *param);
int PQparamCount(PGparam *param);
void PQparamReset(PGparam *param);
void PQparamClear(PGparam *param);
DESCRIPTION
These functions manage the opaque PGparam object.
PQparamCreate() will allocate and initialize a new PGparam object.
After the create call, the PGparam object is ready for use. WARNING:
Only types that have been registered via PQregisterXXX, will be avail‐
able to the param. Meaning, the param is not updated with types regis‐
tered after the param is created.
PQparamDup() will duplicate a given PGparam, including any internal
values that have already been put. This is useful in cases where you
want to queue qeuries to execute at a later time, like a connection
pooler. The problem is PGparamCreate requires a connection object,
which may not be available when attempting to enqueue a query with its
PGparam object. Instead, a PGparam object can used for the sole pur‐
pose of creating duplicates while there are no available PGconn
objects.
PQparamCount() gets the number of parameters in a PGparam object.
PQparamReset() will clear out any previously put parameters, but will
not free any memory. This is useful for application looking to "reuse"
a PGparam object.
PQparamClear() releases all resources being used by a PGparam object,
the object should not be used after a clear.
It is very important to call PQparamReset() if you plan on reusing a
PGparam object.
RETURN VALUEPQparamCreate() returns a pointer to a PGparam object on success and
NULL if something failed (check PQgeterror(3) for more information).
PQparamCount() returns the number of parameters in a PGparam object.
PQparamReset() and PQparamClear() have no return values. If either
function is provided a NULL PGparam pointer, it will silently fail.
EXAMPLES
None.
AUTHOR
A contribution of eSilo, LLC. for the PostgreSQL Database Management
System. Written by Andrew Chernow and Merlin Moncure.
REPORTING BUGS
Report bugs to <libpqtypes@esilo.com>.
COPYRIGHT
Copyright (c) 2011 eSilo, LLC. All rights reserved.
This is free software; see the source for copying conditions. There is
NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE.
SEE ALSOpqt-specs(3), PQputf(3), PQgeterror(3), PQparamExec(3)libpqtypes 2011 PQparamCreate(3)
