#include <libpqtypes.h> /* Always call first on any conn that is to be used with libpqtypes */ PQtypesRegister(conn); /* Instead of using PQexecParams and friends .... */ int resultFormat = 1; PGparam *param = PQparamCreate(conn); /* Pack one or more parameters into a PGparam. */ PQputf(param, "%int4 %text", 654321, "some text"); /* Execute a parameterized query. */ PGresult *res = PQparamExec(conn, param, "INSERT INTO t VALUES ($1, $2)", resultFormat); PQclear(res); /* Release all resources used by `param'. */ PQparamClear(param); /* Or, do all of the above in a single statement! This will put an * int4 and text into a temporary PGparam and execute * "INSERT INTO t VALUES ($1, $2)". */ PGresult *res = PQexecf(conn, "INSERT INTO t VALUES (%int4, %text)", 654321, "some text"); PQclear(res); /* Let's get a composite. * CREATE TYPE simple AS (a int4, t text); */ PGint4 i4; PGtext text; PGresult *simple; /* Your composites need to be registered */ PQregisterTypeHandler(conn, "simple", NULL, NULL); /* 2nd arg, PGparam, can be NULL if there are no query params. * Composites require binary results, so we can't use PQexec(). */ res = PQparamExec(conn, NULL, "SELECT my_simple FROM t", resultFormat); if(!res) fprintf(stderr, "ERROR: %s\n", PQgeterror()); /* Get the simple composite, which is exposed as a PGresult. */ PQgetf(res, 0, "%simple", 0, &simple); PQclear(res); /* no longer needed */ /* Get the simple composite attributes from the simple result. * Reference fields by name by using a '#' rather than a '%'. * The field names are the composite attribute names. */ PQgetf(simple, 0, "#int4 #text", "a", &i4, "t", &text); PQclear(simple);
NOTE:
This requires using postgresql 8.4 (CVS head) for an approved patch that libpqtypes requires
... called libpq-events. To learn more about this new libpq feature, see the
8.4-devel docs.
There is a patch for all 8.3 versions: libpq 8.3 patch.
Package Documents
README
INSTALL
LICENSE
AUTHORS
ChangeLog
Overview Documents
How to Put and Get data types
Describes every structure used by libpqtypes: like PGtimestamp or PGpolygon.
How to handle Composites
Detailed examples for simple, nested and arrays of composites.
Writing Data Type Handlers
Documents structures used by type handlers; includes examples.
Managing PGparam
PQparamCreate
PQparamCount
PQparamReset
PQparamClear
Putting Parameters
PQputf
PQputvf
Executing Commands
PQexecf
PQexecvf
PQparamExec
PQparamExecPrepared
PQparamSendQuery
PQparamSendQueryPrepared
Getting Result Values
PQgetf
Registering Types
PQregisterTypeHandler
Error System
PQgeterror
PQseterror
PQgetErrorField
Misc. Functions
PQspecPrepare
PQtypesRegister
PQlocalTZInfo