PolarDB for PostgreSQL(Compatible with Oracle) is compatible with Oracle databases and provides TO_SINGLE_BYTE and TO_MULTI_BYTE functions. The TO_SINGLE_BYTE function returns a string where all the multibyte characters are converted to the corresponding single-byte characters. The TO_MULTI_BYTE function returns a string where all the single-byte characters are converted to the corresponding multibyte characters.
Usage notes
When you create a PolarDB for PostgreSQL(Compatible with Oracle) database for a PolarDB for PostgreSQL(Compatible with Oracle) cluster created on or after March 30, 2020, the TO_SINGLE_BYTE and TO_MULTI_BYTE plug-ins are automatically created.
When you create a PolarDB for PostgreSQL(Compatible with Oracle) database for a PolarDB for PostgreSQL(Compatible with Oracle) cluster created before March 30, 2020, the plug-ins are not automatically created. To use the plug-ins, you must execute the following statement to manually create the plug-ins after you create the database.
CREATE EXTENSION polar_to_single_byte;For more information about the plug-ins, see TO_SINGLE_BYTE and TO_MULTI_BYTE.
Interfaces
| Function | Data type of the input parameter | Data type of the output |
|---|---|---|
| TO_SINGLE_BYTE | CHAR | CHAR |
| TO_SINGLE_BYTE | CHARACTER VARYING | CHARACTER VARYING |
| TO_SINGLE_BYTE | TEXT | TEXT |
| TO_MULTI_BYTE | CHAR | CHAR |
| TO_MULTI_BYTE | CHARACTER VARYING | CHARACTER VARYING |
| TO_MULTI_BYTE | TEXT | TEXT |
Usage method
-- to_single_byte
SELECT to_single_byte('１２３＄ｔｅｓｔ');
to_single_byte
----------------
123$test
(1 row)
-- to_multi_byte
SELECT to_multi_byte('123$test');
to_multi_byte
------------------
１２３＄ｔｅｓｔ
(1 row)