CHAR (Transact-SQL)
Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW) SQL analytics endpoint in Microsoft Fabric Warehouse in Microsoft Fabric
Returns the single-byte character with the specified integer code, as defined by the character set and encoding of the default collation of the current database.
Transact-SQL syntax conventions
CHAR ( integer_expression )
An integer from 0 through 255. CHAR
returns a NULL
value for integer expressions outside this input range or not representing a complete character.
CHAR
also returns a NULL
value when the character exceeds the length of the return type.
Many common character sets share ASCII as a subset and returns the same character for integer values in the range 0 through 127.
Note
Some character sets, such as Unicode and Shift Japanese Industrial Standards, include characters that can be represented in a single-byte coding scheme, but require multibyte encoding. For more information on character sets, see Single-Byte and Multibyte Character Sets.
char(1)
Use CHAR
to insert control characters into character strings. This table shows some frequently used control characters.
Control character | Value |
---|---|
Tab | char(9) |
Space | char(32) |
Line feed | char(10) |
Carriage return | char(13) |
This example prints the ASCII value and character for each character in the string New Moon
.
SET TEXTSIZE 0;
-- Create variables for the character string and for the current
-- position in the string.
DECLARE @position INT, @string CHAR(8);
-- Initialize the current position and the string variables.
SET @position = 1;
SET @string = 'New Moon';
WHILE @position <= DATALENGTH(@string)
BEGIN
SELECT ASCII(SUBSTRING(@string, @position, 1)),
CHAR(ASCII(SUBSTRING(@string, @position, 1)))
SET @position = @position + 1
END;
GO
Here's the result set.
----------- -
78 N
----------- -
101 e
----------- -
119 w
----------- -
32
----------- -
77 M
----------- -
111 o
----------- -
111 o
----------- -
110 n
This example uses CHAR(13)
to print the name and e-mail address of an employee on separate lines, when the query returns its results as text. This example uses the AdventureWorks2022 database.
SELECT p.FirstName + ' ' + p.LastName + CHAR(13) + pe.EmailAddress
FROM Person.Person p
INNER JOIN Person.EmailAddress pe
ON p.BusinessEntityID = pe.BusinessEntityID
AND p.BusinessEntityID = 1;
GO
Here's the result set.
Ken Sanchez
ken0@adventure-works.com
This example assumes an ASCII character set. It returns the character value for six different ASCII character number values.
SELECT CHAR(65) AS [65], CHAR(66) AS [66],
CHAR(97) AS [97], CHAR(98) AS [98],
CHAR(49) AS [49], CHAR(50) AS [50];
Here's the result set.
65 66 97 98 49 50
---- ---- ---- ---- ---- ----
A B a b 1 2
This example uses CHAR(13)
to return information from sys.databases
on separate lines, when the query returns its results as text.
SELECT name, 'was created on ',
create_date,
CHAR(13),
name,
'is currently ',
state_desc
FROM sys.databases;
GO
Here's the result set.
name create_date name state_desc
--------------------------------------------------------------------------------------------------------------------
master was created on 2003-04-08 09:13:36.390 master is currently ONLINE
tempdb was created on 2014-01-10 17:24:24.023 tempdb is currently ONLINE
AdventureWorksPDW2012 was created on 2014-05-07 09:05:07.083 AdventureWorksPDW2012 is currently ONLINE
This example uses the integer and hex values in the valid range for ASCII. The CHAR function is able to output the single-byte Japanese character.
SELECT CHAR(188) AS single_byte_representing_complete_character,
CHAR(0xBC) AS single_byte_representing_complete_character;
GO
Here's the result set.
single_byte_representing_complete_character single_byte_representing_complete_character
------------------------------------------- -------------------------------------------
シ シ
This example uses integer and hex values in the valid range for Extended ASCII. However, the CHAR
function returns NULL
because the parameter represents only the first byte of a multibyte character. A char(2) double-byte character can't be partially represented nor divided without some conversion operation. The individual bytes of a double-byte character don't generally represent valid char(1) values.
SELECT CHAR(129) AS first_byte_of_double_byte_character,
CHAR(0x81) AS first_byte_of_double_byte_character;
GO
Here's the result set.
first_byte_of_double_byte_character first_byte_of_double_byte_character
----------------------------------- -----------------------------------
NULL NULL
This example accepts the binary value as an encoded multibyte character consistent with the default codepage of the current database, subject to validation. Character conversion is more broadly supported and might be an alternative to working with encoding at a lower level.
CREATE DATABASE [multibyte-char-context] COLLATE Japanese_CI_AI;
GO
USE [multibyte-char-context];
GO
SELECT NCHAR(0x266A) AS [eighth-note],
CONVERT(CHAR(2), 0x81F4) AS [context-dependent-convert],
CAST(0x81F4 AS CHAR(2)) AS [context-dependent-cast];
Here's the result set.
eighth-note context-dependent-convert context-dependent-cast
----------- ------------------------- ----------------------
♪ ♪ ♪
This example highlights the distinction the Unicode standard makes between a character's code point and the code unit sequence under a given encoding form. The binary code assigned to a character in a classic character set is its only numeric identifier.
In contrast, the UTF-8 byte sequence associated with a character is an algorithmic encoding of its assigned numeric identifier: the code point. UTF-8 char and UTF-16 nchar are different encoding forms using 8-bit and 16-bit code units, of the same character set: the Unicode Character Database.
;WITH uni (c)
AS (
-- BMP character
SELECT NCHAR(9835)
UNION ALL
-- non-BMP supplementary character or, under downlevel collation, NULL
SELECT NCHAR(127925)
),
enc (u16c, u8c)
AS (SELECT c, CONVERT(VARCHAR(4), c COLLATE Latin1_General_100_CI_AI_SC_UTF8) FROM uni)
SELECT u16c AS [Music note],
u8c AS [Music note (UTF-8)],
UNICODE(u16c) AS [Code Point],
CONVERT(VARBINARY(4), u16c) AS [UTF-16LE bytes],
CONVERT(VARBINARY(4), u8c) AS [UTF-8 bytes]
FROM enc;
Here's the result set. These results are generated under a _SC
collation with supplementary character support.
Music note | Music note (UTF-8) | Code Point | UTF-16LE bytes | UTF-8 bytes |
---|---|---|---|---|
♫ | ♫ | 9835 | 0x6B26 | 0xE299AB |
🎵 | 🎵 | 127925 | 0x3CD8B5DF | 0xF09F8EB5 |