CREATE [DEFAULT] CONVERSION name FOR source_encoding TO dest_encoding FROM funcname
Description
CREATE CONVERSION defines a new encoding conversion. 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.
Parameters
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) cstring, -- destination string (null terminated C string) integer -- source string length ) RETURNS void;
Notes
Use DROP CONVERSION to remove user-defined conversions.
The privileges required to create a conversion may be changed in a future release.
Examples
To create a conversion from encoding UNICODE to LATIN1 using myfunc:
CREATE CONVERSION myconv FOR 'UNICODE' TO 'LATIN1' FROM myfunc;
Compatibility
CREATE CONVERSION is a PostgreSQL extension. There is no CREATE CONVERSION statement in the SQL standard.
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