CREATE CONVERSION — define a new encoding conversion
CREATE [ DEFAULT ] CONVERSIONname
FORsource_encoding
TOdest_encoding
FROMfuncname
CREATE CONVERSION
defines a new conversion between
character set encodings. Conversion names may be used in the
convert
function
to specify a particular encoding conversion. Also, conversions that
are marked DEFAULT
can be used for automatic encoding
conversion between
client and server. For this purpose, two conversions, from encoding A to
B and from encoding B to A, must be defined.
To be able to create a conversion, you must have EXECUTE
privilege
on the function and CREATE
privilege on the destination schema.
DEFAULT
The DEFAULT
clause indicates that this conversion
is the default for this particular source to destination
encoding. There should be only one default encoding in a schema
for the encoding pair.
name
The name of the conversion. The conversion name may be schema-qualified. If it is not, the conversion is defined in the current schema. The conversion name must be unique within a schema.
source_encoding
The source encoding name.
dest_encoding
The destination encoding name.
funcname
The function used to perform the conversion. The function name may be schema-qualified. If it is not, the function will be looked up in the path.
The function must have the following signature:
conv_proc( integer, -- source encoding ID integer, -- destination encoding ID cstring, -- source string (null terminated C string) internal, -- destination (fill with a null terminated C string) integer -- source string length ) RETURNS void;
Use DROP CONVERSION
to remove user-defined conversions.
The privileges required to create a conversion may be changed in a future release.
To create a conversion from encoding UTF8
to
LATIN1
using myfunc
:
CREATE CONVERSION myconv FOR 'UTF8' TO 'LATIN1' FROM myfunc;