Oracle® Database SQL Reference 10g Release 2 (10.2) Part Number B14200-01 |
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Syntax
Purpose
CONVERT
converts a character string from one character set to another. The datatype of the returned value is VARCHAR2
.
The char
argument is the value to be converted. It can be any of the datatypes CHAR
, VARCHAR2
, NCHAR
, NVARCHAR2
, CLOB
, or NCLOB
.
The dest_char_set
argument is the name of the character set to which char
is converted.
The source_char_set
argument is the name of the character set in which char
is stored in the database. The default value is the database character set.
Both the destination and source character set arguments can be either literals or columns containing the name of the character set.
For complete correspondence in character conversion, it is essential that the destination character set contains a representation of all the characters defined in the source character set. Where a character does not exist in the destination character set, a replacement character appears. Replacement characters can be defined as part of a character set definition.
Examples
The following example illustrates character set conversion by converting a Latin-1 string to ASCII. The result is the same as importing the same string from a WE8ISO8859P1 database to a US7ASCII database.
SELECT CONVERT('Ä Ê Í Ó Ø A B C D E ', 'US7ASCII', 'WE8ISO8859P1') FROM DUAL; CONVERT('ÄÊÍÓØABCDE' --------------------- A E I ? ? A B C D E ?
Common character sets include:
US7ASCII: US 7-bit ASCII character set
WE8DEC: West European 8-bit character set
F7DEC: DEC French 7-bit character set
WE8EBCDIC500: IBM West European EBCDIC Code Page 500
WE8ISO8859P1: ISO 8859-1 West European 8-bit character set
UTF8: Unicode 4.0 UTF-8 Universal character set, CESU-8 compliant
AL32UTF8: Unicode 4.0 UTF-8 Universal character set