1odbx_get_option(3) OpenDBX odbx_get_option(3)
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6 odbx_get_option - Query backend for implemented options
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9 #include <opendbx/api.h>
10 int odbx_get_option (odbx_t* handle, unsigned int option, void* value);
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15 odbx_get_option() asks the backend module associated to handle by
16 odbx_init() for implemented options and their current values. This
17 function can be used at every stage as long as handle points to a valid
18 connection object. Its primary use is to find out supported features of
19 the backend module and to enable them with odbx_set_option() before the
20 connection to the database server is established by calling
21 odbx_bind().
22 The first parameter handle is the connection object created and re‐
24 turned by odbx_init() which becomes invalid as soon as it was supplied
25 to odbx_finish().
26 There are several option values defined as named constants in the
28 odbx.h header file. A few of them are for informational purpose only
29 while most of the options can also be set to different option values by
30 odbx_set_option() to change the behavior of the backend module. The
31 available options are:
32 ODBX_OPT_API_VERSION
34 The API version implemented by the backend. Currently, it re‐
35 turns only zero and is reserved for the future
36 ODBX_OPT_THREAD_SAFE
38 If it is safe to use this backend and especially the native
39 database client library in an application which uses threads
40 where more than one thread opens database connections via the
41 OpenDBX library
42 ODBX_OPT_TLS
44 The database client library may support transmitting all data
45 securely by encrypting the network traffic via SSL or TLS
46 ODBX_OPT_MULTI_STATEMENTS
48 The database server may be able to support multiple SQL state‐
49 ments in one query string sent via odbx_query()
50 ODBX_OPT_PAGED_RESULTS
52 All database servers and client libraries are able to transfer
53 the records row by row. Some of them can also transfer multiple
54 rows or even all at once to minimize server load, network traf‐
55 fic and latency. The downside of this is an increased memory
56 consumption
57 ODBX_OPT_COMPRESS
59 Support of compressed network traffic between database client
60 and server. This can lead to higher throughput if the network is
61 the bottleneck
62 ODBX_OPT_MODE
64 Some database servers support different modes of operation, e.g.
65 modes for compliance to other SQL implementations or completely
66 different query languages. This option is available since OpenD‐
67 BX 1.1.4
68 value must be a pointer to an integer variable where the backend module
70 will store the result for the supplied option. If it's not stated oth‐
71 erwise, the value assigned to the value parameter by odbx_get_option()
72 will be of boolean nature and therefore is ODBX_ENABLE for a supported
73 option or ODBX_DISABLE for an option which isn't supported.
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76 odbx_get_option() returns ODBX_ERR_SUCCESS, or an error code whose val‐
77 ue is less than zero if one of the operations couldn't be completed
78 successfully. Possible error codes are listed in the error section and
79 they can be feed to odbx_error() and odbx_error_type() to get further
80 details.
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83 -ODBX_ERR_PARAM
84 One of the supplied parameters is invalid or is NULL and this
85 isn't allowed in the used backend module or in the native data‐
86 base client library
87 -ODBX_ERR_OPTION
89 The value passed to the option parameter isn't one of the values
90 listed in this manual. The content of value remains unchanged if
91 this error occurs
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94 odbx_bind(), odbx_error(), odbx_error_type(), odbx_init(), odbx_set_op‐
95 tion()
96 2 February 2021 odbx_get_option(3)