CHR

Syntax

Description of the illustration chr.gif

Purpose

CHR returns the character having the binary equivalent to n as a VARCHAR2 value in either the database character set or, if you specify USING NCHAR_CS, the national character set.

For single-byte character sets, if n > 256, then Oracle Database returns the binary equivalent of n mod 256. For multibyte character sets, n must resolve to one entire code point. Invalid code points are not validated, and the result of specifying invalid code points is indeterminate.

This function takes as an argument a NUMBER value, or any value that can be implicitly converted to NUMBER, and returns a character.

Examples

The following example is run on an ASCII-based machine with the database character set defined as WE8ISO8859P1:

SELECT CHR(67)||CHR(65)||CHR(84) "Dog" FROM DUAL;

Dog
---
CAT

To produce the same results on an EBCDIC-based machine with the WE8EBCDIC1047 character set, the preceding example would have to be modified as follows:

SELECT CHR(195)||CHR(193)||CHR(227) "Dog" 
   FROM DUAL; 

Dog 
--- 
CAT 

For multibyte character sets, this sort of concatenation gives different results. For example, given a multibyte character whose hexadecimal value is a1a2 (a1 representing the first byte and a2 the second byte), you must specify for n the decimal equivalent of 'a1a2', or 41378. That is, you must specify:

SELECT CHR(41378) FROM DUAL;

You cannot specify the decimal equivalent of a1 concatenated with the decimal equivalent of a2, as in the following example:

SELECT CHR(161)||CHR(162) FROM DUAL;

However, you can concatenate whole multibyte code points, as in the following example, which concatenates the multibyte characters whose hexadecimal values are a1a2 and a1a3:

SELECT CHR(41378)||CHR(41379) FROM DUAL;

The following example assumes that the national character set is UTF16:

SELECT CHR (196 USING NCHAR_CS) FROM DUAL; 

CH 
-- 
Ä