Postgres-XC 1.1 Documentation | ||||
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Note: At present, this section is just taken from PostgreSQL documentation and is subject to revision for Postgres-XC.
The plpy module also provides the functions
plpy.debug(msg),
plpy.log(msg),
plpy.info(msg),
plpy.notice(msg),
plpy.warning(msg),
plpy.error(msg), and
plpy.fatal(msg).
plpy.error
and
plpy.fatal
actually raise a Python exception
which, if uncaught, propagates out to the calling query, causing
the current transaction or subtransaction to be aborted.
raise plpy.Error(msg) and
raise plpy.Fatal(msg) are
equivalent to calling
plpy.error
and
plpy.fatal
, respectively.
The other functions only generate messages of different
priority levels.
Whether messages of a particular priority are reported to the client,
written to the server log, or both is controlled by the
log_min_messages and
client_min_messages configuration
variables. See Chapter 17 for more information.
Another set of utility functions are plpy.quote_literal(string), plpy.quote_nullable(string), and plpy.quote_ident(string). They are equivalent to the built-in quoting functions described in Section 9.4. They are useful when constructing ad-hoc queries. A PL/Python equivalent of dynamic SQL from Example 40-1 would be:
plpy.execute("UPDATE tbl SET %s = %s WHERE key = %s" % ( plpy.quote_ident(colname), plpy.quote_nullable(newvalue), plpy.quote_literal(keyvalue)))