CREATE CONVERSSQL(-)Language Statements (2002CREATE)CONVERSION(l)
NAME
CREATE CONVERSION - define a user-defined conversion
SYNOPSIS
CREATE [DEFAULT] CONVERSION 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 frontend and backend. 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 the execute
right on the function and the create right 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.
conversion_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.
source_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
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CREATE CONVERSSQL(-)Language Statements (2002CREATE)CONVERSION(l)
) 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 SQL99.
SEE ALSO
CREATE FUNCTION [create_function(l)], DROP CONVERSION
[drop_conversion(l)], PostgreSQL Programmer's Guide
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