These functions control miscellaneous details of libpq's behavior.
PQclientEncodingReturns 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);
PQsetClientEncodingSets 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,
PQERRORS_SQLSTATE
} 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. The SQLSTATE
mode includes only the error severity and the SQLSTATE
error code, if one is available (if not, the output is like
TERSE mode).
Changing the verbosity setting 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.
The NEVER mode
never includes CONTEXT, while ALWAYS always
includes it if available. In ERRORS mode (the
default), CONTEXT fields are included only in error
messages, not in notices and warnings.
(However, if the verbosity setting is TERSE
or SQLSTATE, CONTEXT fields
are omitted regardless of the context display mode.)
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.)
PQtraceEnables tracing of the client/server communication to a debugging file stream.
void PQtrace(PGconn *conn, FILE *stream);
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);