PostgreSQL 9.4.1 Documentation | |||
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31.10. Control Functions
These functions control miscellaneous details oflibpq's behavior.
PQclientEncoding
Returns the client encoding.
int PQclientEncoding(const PGconn *conn);
Note that it returns the encoding ID, not a symbolic string such asEUC_JP. If unsuccessful, it returns -1. To convert an encoding ID to an encoding name, you can use:
char *pg_encoding_to_char(intencoding_id);
PQsetClientEncoding
Sets the client encoding.
int PQsetClientEncoding(PGconn *conn, const char *encoding);
conn is a connection to the server, andencoding 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
andPQresultErrorMessage
.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. InTERSE 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). TheVERBOSE mode includes all available fields. Changing the verbosity does not affect the messages available from already-existingPGresult objects, only subsequently-created ones.PQtrace
Enables tracing of the client/server communication to a debugging file stream.
void PQtrace(PGconn *conn, FILE *stream);
Note: On Windows, if thelibpq library and an application are compiled with different flags, this function call will crash the application because the internal representation of theFILE 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);