CREATE CONVERSION

Description

Defines a new conversion between two character set encodings. This function is for internal use only. You are advised not to use it.

Precautions

The DEFAULT parameter indicates that the conversion between the source encoding and the target encoding is executed by default between the client and the server. To support this usage, bidirectional conversion must be defined, that is, both conversion from A to B and conversion from B to A are supported.
To perform conversion, you must have the EXECUTE permission on function and the CREATE permission on the target schema.
SQL_ASCII cannot be used for either source encoding or target encoding because the server behavior is hardwired when SQL_ASCII "encoding" is involved.
You can remove user-defined conversions using DROP CONVERSION.

Syntax

CREATE [ DEFAULT ] CONVERSION name
    FOR 'source_encoding' TO 'dest_encoding' FROM function_name;

Parameters

DEFAULT
Specifies that the conversion is the default conversion from the source encoding to the target encoding. There should be only one default conversion for each encoding pair in a schema.
name
Specifies the name of the conversion, which can be restricted by the schema. If not restricted by a schema, the conversion is defined in the current schema. The conversion name must be unique in a schema.
source_encoding
Source encoding name.
dest_encoding
Target encoding name.

function_name

Function used for conversion. A function name can be restricted by a schema. If not, the function is found in the path.

The function must be in the following format:

conv_proc(
    integer, -- Source encoding ID
    integer, -- Target encoding ID
    cstring, -- Source character string (C character string ending with a null value)
    internal,-- Target (filled with a null-terminated C character string)
    integer  -- Length of the source string
) RETURNS void;