How to Use UTF-8 Collation in SQL Server database? - sql-server

Question

I've migrated a database from mysql to SQL Server (politics), original mysql database using UTF8.
Now I read https://dba.stackexchange.com/questions/7346/sql-server-2005-2008-utf-8-collation-charset that SQL Server 2008 doesn't support utf8, is this a joke?
The SQL Server hosts multiple databases, mostly Latin-encoded. Since the migrated db is intended for web publishing, I want to keep the utf8-encoding. Have I missed something or do I need to enc/dec at application level?

Answer 1

UTF-8 is not a character set, it's an encoding. The character set for UTF-8 is Unicode. If you want to store Unicode text you use the nvarchar data type.
If the database would use UTF-8 to store text, you would still not get the text out as encoded UTF-8 data, you would get it out as decoded text.
You can easily store UTF-8 encoded text in the database, but then you don't store it as text, you store it as binary data (varbinary).

Answer 2

Looks like this will be finally supported in the SQL Server 2019!
SQL Server 2019 - whats new?
From BOL:
UTF-8 support
Full support for the widely used UTF-8 character encoding as an import
or export encoding, or as database-level or column-level collation for
text data. UTF-8 is allowed in the CHAR and VARCHAR datatypes, and is
enabled when creating or changing an object’s collation to a collation
with the UTF8 suffix.
For example,LATIN1_GENERAL_100_CI_AS_SC to
Latin1_General_100_CI_AS_KS_SC_UTF8. UTF-8 is only available to Windows
collations that support supplementary characters, as introduced in SQL
Server 2012. NCHAR and NVARCHAR allow UTF-16 encoding only, and remain
unchanged.
This feature may provide significant storage savings, depending on the
character set in use. For example, changing an existing column data
type with ASCII strings from NCHAR(10) to CHAR(10) using an UTF-8
enabled collation, translates into nearly 50% reduction in storage
requirements. This reduction is because NCHAR(10) requires 22 bytes
for storage, whereas CHAR(10) requires 12 bytes for the same Unicode
string.
2019-05-14 update:
Documentation seems to be updated now and explains our options staring in MSSQL 2019 in section "Collation and Unicode Support".
2019-07-24 update:
Article by Pedro Lopes - Senior Program Manager # Microsoft about introducing UTF-8 support for Azure SQL Database

Answer 3

No! It's not a joke.
Take a look here: http://msdn.microsoft.com/en-us/library/ms186939.aspx
Character data types that are either fixed-length, nchar, or
variable-length, nvarchar, Unicode data and use the UNICODE UCS-2
character set.
And also here: http://en.wikipedia.org/wiki/UTF-16
The older UCS-2 (2-byte Universal Character Set) is a similar
character encoding that was superseded by UTF-16 in version 2.0 of the
Unicode standard in July 1996.

Answer 4

Two UDF to deal with UTF-8 in T-SQL:
CREATE Function UcsToUtf8(#src nvarchar(MAX)) returns varchar(MAX) as
begin
declare #res varchar(MAX)='', #pi char(8)='%[^'+char(0)+'-'+char(127)+']%', #i int, #j int
select #i=patindex(#pi,#src collate Latin1_General_BIN)
while #i>0
begin
select #j=unicode(substring(#src,#i,1))
if #j<0x800 select #res=#res+left(#src,#i-1)+char((#j&1984)/64+192)+char((#j&63)+128)
else select #res=#res+left(#src,#i-1)+char((#j&61440)/4096+224)+char((#j&4032)/64+128)+char((#j&63)+128)
select #src=substring(#src,#i+1,datalength(#src)-1), #i=patindex(#pi,#src collate Latin1_General_BIN)
end
select #res=#res+#src
return #res
end
CREATE Function Utf8ToUcs(#src varchar(MAX)) returns nvarchar(MAX) as
begin
declare #i int, #res nvarchar(MAX)=#src, #pi varchar(18)
select #pi='%[à-ï][€-¿][€-¿]%',#i=patindex(#pi,#src collate Latin1_General_BIN)
while #i>0 select #res=stuff(#res,#i,3,nchar(((ascii(substring(#src,#i,1))&31)*4096)+((ascii(substring(#src,#i+1,1))&63)*64)+(ascii(substring(#src,#i+2,1))&63))), #src=stuff(#src,#i,3,'.'), #i=patindex(#pi,#src collate Latin1_General_BIN)
select #pi='%[Â-ß][€-¿]%',#i=patindex(#pi,#src collate Latin1_General_BIN)
while #i>0 select #res=stuff(#res,#i,2,nchar(((ascii(substring(#src,#i,1))&31)*64)+(ascii(substring(#src,#i+1,1))&63))), #src=stuff(#src,#i,2,'.'),#i=patindex(#pi,#src collate Latin1_General_BIN)
return #res
end

Answer 5

Note that as of Microsoft SQL Server 2016, UTF-8 is supported by bcp, BULK_INSERT, and OPENROWSET.
Addendum 2016-12-21: SQL Server 2016 SP1 now enables Unicode Compression (and most other previously Enterprise-only features) for all versions of MS SQL including Standard and Express. This is not the same as UTF-8 support, but it yields a similar benefit if the goal is disk space reduction for Western alphabets.