NameCREATE CONVERSION -- define a user-defined conversion SynopsisCREATE [DEFAULT] CONVERSION conversion_name
FOR source_encoding TO dest_encoding FROM funcnameDescription 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
) 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. |
