PostgreSQL 9.6.0 Documentation | |||
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These functions control miscellaneous details of libpq's behavior.
PQclientEncoding
Returns the client encoding.
int PQclientEncoding(const PGconn *conn);
Note that it returns the encoding ID, not a symbolic string such as EUC_JP. If unsuccessful, it returns -1. To convert an encoding ID to an encoding name, you can use:
char *pg_encoding_to_char(int encoding_id);
PQsetClientEncoding
Sets the client encoding.
int PQsetClientEncoding(PGconn *conn, const char *encoding);
conn is a connection to the server,
and encoding is the encoding you want to
use. If the function successfully sets the encoding, it returns 0,
otherwise -1. The current encoding for this connection can be
determined by using PQclientEncoding
.
PQsetErrorVerbosity
Determines the verbosity of messages returned by
PQerrorMessage
and PQresultErrorMessage
.
typedef enum { PQERRORS_TERSE, PQERRORS_DEFAULT, PQERRORS_VERBOSE } PGVerbosity; PGVerbosity PQsetErrorVerbosity(PGconn *conn, PGVerbosity verbosity);
PQsetErrorVerbosity
sets the verbosity mode, returning
the connection's previous setting. In TERSE mode,
returned messages include severity, primary text, and position only;
this will normally fit on a single line. The default mode produces
messages that include the above plus any detail, hint, or context
fields (these might span multiple lines). The VERBOSE
mode includes all available fields. Changing the verbosity does not
affect the messages available from already-existing
PGresult objects, only subsequently-created ones.
(But see PQresultVerboseErrorMessage
if you
want to print a previous error with a different verbosity.)
PQsetErrorContextVisibility
Determines the handling of CONTEXT fields in messages
returned by PQerrorMessage
and PQresultErrorMessage
.
typedef enum { PQSHOW_CONTEXT_NEVER, PQSHOW_CONTEXT_ERRORS, PQSHOW_CONTEXT_ALWAYS } PGContextVisibility; PGContextVisibility PQsetErrorContextVisibility(PGconn *conn, PGContextVisibility show_context);
PQsetErrorContextVisibility
sets the context display mode,
returning the connection's previous setting. This mode controls
whether the CONTEXT field is included in messages
(unless the verbosity setting is TERSE, in which
case CONTEXT is never shown). The NEVER mode
never includes CONTEXT, while ALWAYS always
includes it if available. In ERRORS mode (the
default), CONTEXT fields are included only for error
messages, not for notices and warnings. Changing this mode does not
affect the messages available from
already-existing PGresult objects, only
subsequently-created ones.
(But see PQresultVerboseErrorMessage
if you
want to print a previous error with a different display mode.)
PQtrace
Enables tracing of the client/server communication to a debugging file stream.
void PQtrace(PGconn *conn, FILE *stream);
Note: On Windows, if the libpq library and an application are compiled with different flags, this function call will crash the application because the internal representation of the FILE pointers differ. Specifically, multithreaded/single-threaded, release/debug, and static/dynamic flags should be the same for the library and all applications using that library.
PQuntrace
Disables tracing started by PQtrace
.
void PQuntrace(PGconn *conn);