Contents
to_ascii()
to_ascii() is a system function for converting a string from a small range of other encodings.
to_ascii() was added in PostgreSQL 7.1.
Usage
to_ascii(stringTEXT)
to_ascii(stringTEXT,encodingNAME)
to_ascii(stringTEXT,encodingINTEGER)
In practice, the first form, which defaults to the current database encoding, is the only variant of practical use.
Conversions from the following encodings are supported:
| Encoding | Number |
|---|---|
LATIN1 |
8 |
LATIN2 |
9 |
LATIN9 |
16 |
WIN1250 |
29 |
The PostgreSQL documentation does not specify the encoding numbers noted in the preceding table; these correspond to the matching values in the pg_enc enum defined in src/include/mb/pg_wchar.h.
The contrib module unaccent provides a more flexible range of options to achieve the same objective.
Change history
- PostgreSQL 8.0
- support for the
LATIN9encoding added (commit 75b61043)
- support for the
- PostgreSQL 7.1
- added (commit dffd8cac)
Examples
Basic usage:
asciitest=# SELECT to_ascii('überbewertete äthiopische Ödnis');
to_ascii
---------------------------------
uberbewertete athiopische Odnis
(1 row)
The same result using the encoding name and number respectively:
asciitest=# SELECT to_ascii('überbewertete äthiopische Ödnis', 'LATIN1');
to_ascii
---------------------------------
uberbewertete athiopische Odnis
(1 row)
asciitest=# SELECT to_ascii('überbewertete äthiopische Ödnis', 8);
to_ascii
---------------------------------
uberbewertete athiopische Odnis
(1 row)
Attempting to convert from unsupported or invalid encodings:
asciitest=# SELECT to_ascii('ü', 'EUC_JP');
ERROR: encoding conversion from EUC_JP to ASCII not supported
asciitest=# SELECT to_ascii('ü', 19);
ERROR: encoding conversion from WIN1258 to ASCII not supported
asciitest=# SELECT to_ascii('ü', 99);
ERROR: 99 is not a valid encoding code
to_ascii() produces garbage output when executed in a database not in one of the supported encodings:
postgres=# \l postgres
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
----------+----------+----------+-------------+-------------+-------------------
postgres | postgres | UTF8 | de_DE.UTF-8 | de_DE.UTF-8 |
(1 row)
postgres=# SELECT to_ascii('äü');
to_ascii
----------
A A
(1 row)
References
- PostgreSQL documentation: Other String Functions