� IN SQL Server database

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 #demovalues(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/

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 TWHERE N LIKE '%[' +  NCHAR(65533) + NCHAR(55296) + '-' + NCHAR(57343) + ']%' COLLATE Latin1_General_100_BIN

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 Sometablewhere 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)GOinsert into sometablevalues ('12345'),('123�45'),('12345')GOselect * from sometablewhere 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'�'))GOcreate table sometable(somecolumn nvarchar(100) not null)GOinsert into sometablevalues ('12345'),('123�45'),('12345'),('12'+NCHAR(UNICODE(N'�'))+'345')GOselect * from sometablewhere somecolumn like '%'+CHAR(63)+'%'select * from sometablewhere somecolumn like '%'+NCHAR(UNICODE(N'�'))+'%'GO