Oracle CHR() Function

Oracle CHR() is a built-in function that returns the character corresponding to the given integer parameter.

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

Oracle CHR() syntax

Here is the syntax for the Oracle CHR() function:

CHR(n)
CHR(n USING NCHAR_CS)

Parameters

n

Required. A value of NUMBER type or any expression that can be implicitly converted to a NUMBER value.

USING NCHAR_CS

Optional. It indicates to use national character sets.

Return Value

The Oracle CHR() function returns the character having the binary equivalent to the gaven number 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 is greater than 256, Oracle Database returns the binary equivalent of n mod 256.

For multibyte character sets, n must resolve to a full code point. Invalid code points are not validated, and the result of specifying an invalid code point is undefined.

If any parameter is NULL, CHR() will return NULL.

Oracle CHR() Examples

Here are some examples that demonstrate the usage of the Oracle CHR() function.

Basic Usage

The following statement uses the Oracle CHR() function to convert 67 to a character:

SELECT CHR(67)
FROM dual;

Output:

CHR(67)
__________
C

If the parameter n is greater than 256, the binary equivalent returned by Oracle Database is n mod 256.

SELECT
    CHR(67),
    CHR(67 + 256)
FROM dual;

Output:

CHR(67)    CHR(67+256)
__________ ______________
C          C

USING NCHAR_CS

Oracle CHR() allows you to use national character sets.

SELECT CHR (257 USING NCHAR_CS)
FROM dual;

Output:

CHR(257USINGNCHAR_CS)
________________________
ā

This is the same as using the NCHR() function.

NULL Parameters

If any parameter is NULL, CHR() will return NULL.

SET NULL 'NULL';
SELECT
    CHR(NULL)
FROM dual;

Output:

CHR(NULL)
____________
NULL

In this example, we use the statement SET NULL 'NULL'; to display NULL values as the string 'NULL'.

Conclusion

Oracle CHR() is a built-in function that returns the character corresponding to the given integer parameter.