� IN SQL Server database - sql

Question

in my database I have this char �. I want to locate them with a query
Select *
from Sometable
where somecolumn like '%�%'
this gets me no result.
I think it is ANSI encoding

Answer 1

use N like below
where col like N'%�%'
why do you think ,you need N prefix:
Prefix Unicode character string constants with the letter N. Without the N prefix, the string is converted to the default code page of the database. This default code page may not recognize certain characters.
Thanks to Martin Smith,Earlier i tested only with one character earlier and it worked,but as Martin pointed out, it returns all characters..
Below query works and returns only intended
select * from #demo where id like N'%�%'
COLLATE Latin1_General_100_BIN
Demo:
create table #demo
(
id nvarchar(max)
)
insert into #demo
values
(N'ﬗ'),
( N'�')
to know more about unicode,please see below links
http://kunststube.net/encoding/
https://www.joelonsoftware.com/2003/10/08/the-absolute-minimum-every-software-developer-absolutely-positively-must-know-about-unicode-and-character-sets-no-excuses/

Answer 2

This is the Unicode replacement character symbol.
It could match any of 2,048 invalid code points in the UCS-2 encoding (or the single character U+FFFD for the symbol itself).
You can use a range and a binary collate clause to match them all (demo).
WITH T(N)
AS
(
SELECT TOP 65536 NCHAR(ROW_NUMBER() OVER (ORDER BY ##SPID))
FROM master..spt_values v1,
master..spt_values v2
)
SELECT N
FROM T
WHERE N LIKE '%[' + NCHAR(65533) + NCHAR(55296) + '-' + NCHAR(57343) + ']%' COLLATE Latin1_General_100_BIN

Answer 3

You can use ASCII to find out the ascii code for that char
Select ascii('�')
And use CHAR to retrieve the char from that code and combine it in a LIKE expression
Select * from Sometable
where somecolumn like '%'+CHAR(63)+'%'
Note the collation you use can affect the result. Also it depends on the encoding used by your application to feed your data (UTF-8, UNICODE, etc). also how you store it VARCHAR, or NVARCHAR has a last say on what you see.
There's more here in this similar question
EDIT
#Mark
try this simple test:
create table sometable(somecolumn nvarchar(100) not null)
GO
insert into sometable
values
('12345')
,('123�45')
,('12345')
GO
select * from sometable
where somecolumn like '%'+CHAR(63)+'%'
GO
This only means that character was stored win the as a "?" in this test.
When you see a � it means the app where you are seeing isn't quite sure what to print out.
It also mean OP probably needs to find out what char is that using a query.
Also note it means a string outputted like ��� can be 3 formed by different characters.
CHAR(63) was just an example, but you are right this in the ASCII table will be a standard interrogation.
EDIT
#Bridge
Not with time right now to deep dig in it but the below test don't worked
Select ascii('�'), CHAR(ascii('�')), UNICODE(N'�'), CHAR(UNICODE(N'�'))
GO
create table sometable(somecolumn nvarchar(100) not null)
GO
insert into sometable
values
('12345')
,('123�45')
,('12345')
,('12'+NCHAR(UNICODE(N'�'))+'345')
GO
select * from sometable
where somecolumn like '%'+CHAR(63)+'%'
select * from sometable
where somecolumn like '%'+NCHAR(UNICODE(N'�'))+'%'
GO