The plpy
module also provides the functions
plpy.debug( |
plpy.log( |
plpy.info( |
plpy.notice( |
plpy.warning( |
plpy.error( |
plpy.fatal( |
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(
and
msg
)raise plpy.Fatal(
are
equivalent to calling msg
)plpy.error(
and
msg
)plpy.fatal(
, respectively but
the msg
)raise
form does not allow passing keyword arguments.
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.
The msg
argument is given as a positional argument. For
backward compatibility, more than one positional argument can be given. In
that case, the string representation of the tuple of positional arguments
becomes the message reported to the client.
The following keyword-only arguments are accepted:
detail |
hint |
sqlstate |
schema_name |
table_name |
column_name |
datatype_name |
constraint_name |
The string representation of the objects passed as keyword-only arguments is used to enrich the messages reported to the client. For example:
CREATE FUNCTION raise_custom_exception() RETURNS void AS $$ plpy.error("custom exception message", detail="some info about exception", hint="hint for users") $$ LANGUAGE plpythonu; =# SELECT raise_custom_exception(); ERROR: plpy.Error: custom exception message DETAIL: some info about exception HINT: hint for users CONTEXT: Traceback (most recent call last): PL/Python function "raise_custom_exception", line 4, in <module> hint="hint for users") PL/Python function "raise_custom_exception"
Another set of utility functions are
plpy.quote_literal(
,
string
)plpy.quote_nullable(
, and
string
)plpy.quote_ident(
. 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 41.1 would be:
string
)
plpy.execute("UPDATE tbl SET %s = %s WHERE key = %s" % ( plpy.quote_ident(colname), plpy.quote_nullable(newvalue), plpy.quote_literal(keyvalue)))