Convert Unicode Hex Codepoint to Unicode Character in SQL Server

The Unicode standard uses the notation U+[x]xxxx to identify each Unicode character, i.e. “U+” followed by 4 or 5 hex digits.

If we remove the first 2 characters (as in the UCD), only hex digits will remain, and we need to convert them to an integer. Using this HexStrToVarBinary function, we get the binary representation of the hex number, which can than be CONVERTed to an int or bigint.

Next, we use the built-in NCHAR() function to create an NCHAR value of the int.

SELECT  UniHex,
        CONVERT(INT, dbo.HexStrToVarBinary(UniHex)) AS UniInt,
        NCHAR(CONVERT(INT, dbo.HexStrToVarBinary(UniHex))) AS UniNChar
FROM    UniHexTable

Note that the NCHAR() function only works with int arguments from 0 to 65535, so surrogate characters are not handled, and NCHAR() returns NULL.

SQL Server stores Unicode data encoded as UCS-2, and therefore does not support supplementary characters (surrogate pairs).

Unicode Versions supported in SQL Server

SQL Server	Unicode
2000	3.0 ?
2005	3.2
2008	5.0

(I did not find an explicit statement on SQL2000, so this is a guess based on the release of SQL Server 2000 and the release date of Unicode 3.0)

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