CREATE CONVERSION

Function

CREATE CONVERSION defines a new conversion between two character set encodings.

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

Parameter Description

• 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.

  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;

Example

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-- Use myfunc to create an encoding conversion from UTF8 to LATIN1.
CREATE CONVERSION myconv FOR 'UTF8' TO 'LATIN1' FROM myfunc;