bionic (3) odbx_get_option.3.gz
NAME
odbx_get_option - Query backend for implemented options
SYNOPSIS
#include <opendbx/api.h>
int odbx_get_option (odbx_t* handle, unsigned int option, void* value);
DESCRIPTION
odbx_get_option() asks the backend module associated to handle by odbx_init() for implemented options and
their current values. This function can be used at every stage as long as handle points to a valid
connection object. Its primary use is to find out supported features of the backend module and to enable
them with odbx_set_option() before the connection to the database server is established by calling
odbx_bind().
The first parameter handle is the connection object created and returned by odbx_init() which becomes
invalid as soon as it was supplied to odbx_finish().
There are several option values defined as named constants in the odbx.h header file. A few of them are
for informational purpose only while most of the options can also be set to different option values by
odbx_set_option() to change the behavior of the backend module. The available options are:
ODBX_OPT_API_VERSION
The API version implemented by the backend. Currently, it returns only zero and is reserved for
the future
ODBX_OPT_THREAD_SAFE
If it is safe to use this backend and especially the native database client library in an
application which uses threads where more than one thread opens database connections via the
OpenDBX library
ODBX_OPT_TLS
The database client library may support transmitting all data securely by encrypting the network
traffic via SSL or TLS
ODBX_OPT_MULTI_STATEMENTS
The database server may be able to support multiple SQL statements in one query string sent via
odbx_query()
ODBX_OPT_PAGED_RESULTS
All database servers and client libraries are able to transfer the records row by row. Some of
them can also transfer multiple rows or even all at once to minimize server load, network traffic
and latency. The downside of this is an increased memory consumption
ODBX_OPT_COMPRESS
Support of compressed network traffic between database client and server. This can lead to higher
throughput if the network is the bottleneck
ODBX_OPT_MODE
Some database servers support different modes of operation, e.g. modes for compliance to other SQL
implementations or completely different query languages. This option is available since OpenDBX
1.1.4
value must be a pointer to an integer variable where the backend module will store the result for the
supplied option. If it's not stated otherwise, the value assigned to the value parameter by
odbx_get_option() will be of boolean nature and therefore is ODBX_ENABLE for a supported option or
ODBX_DISABLE for an option which isn't supported.
RETURN VALUE
odbx_get_option() returns ODBX_ERR_SUCCESS, or an error code whose value is less than zero if one of the
operations couldn't be completed successfully. Possible error codes are listed in the error section and
they can be feed to odbx_error() and odbx_error_type() to get further details.
ERRORS
-ODBX_ERR_PARAM
One of the supplied parameters is invalid or is NULL and this isn't allowed in the used backend
module or in the native database client library
-ODBX_ERR_OPTION
The value passed to the option parameter isn't one of the values listed in this manual. The
content of value remains unchanged if this error occurs
SEE ALSO
odbx_bind(), odbx_error(), odbx_error_type(), odbx_init(), odbx_set_option()
21 October 2016 odbx_get_option(3)