create table #t (string varchar (5))

insert into #t (string) values ('ACH')
insert into #t (string) values ('ACY')
insert into #t (string) values ('AHHC')

select string from #t
where string like '%C%' -- will miss ACH

drop table #t

create table #t (string varchar (5))

insert into #t (string) values ('ACH')
insert into #t (string) values ('ACY')
insert into #t (string) values ('AHHC')

select string from #t
where string COLLATE Czech_BIN like '%C%' -- won't miss ACH

drop table #t

SET NOCOUNT ON;

DECLARE @name SYSNAME;

DECLARE cur CURSOR LOCAL STATIC FOR
  SELECT  name
  FROM    ::fn_helpcollations();

CREATE TABLE #result (collation SYSNAME, string VARCHAR(2));

OPEN cur;

FETCH NEXT FROM cur INTO @name;

WHILE @@FETCH_STATUS = 0
BEGIN
  EXEC('ALTER TABLE #t ALTER COLUMN string VARCHAR(2) COLLATE ' + @name);

  IF @@ERROR = 0  
    INSERT #result (collation, string)
    SELECT @name, string
    FROM   #t
    WHERE  string LIKE '_';
  

  FETCH NEXT FROM cur INTO @name;
END;

CLOSE cur;

DEALLOCATE cur;

SELECT DISTINCT collation FROM #result;

SELECT DISTINCT collation, UPPER(string) FROM #result;

DROP TABLE #result;

CREATE TABLE #t ([string] VARCHAR (5));

INSERT INTO #t ([string]) 
	VALUES ('ACH');
INSERT INTO #t ([string])
	VALUES ('ACY');
INSERT INTO #t ([string]) 
	VALUES ('AHHC');

-- Output: 1. ACY, 2. AHHC, 3. ACH
SELECT 
	Row_Number() OVER (ORDER BY [string]), [string] 
FROM 
	#t;
	
-- Output: 1. ACH, 2. ACY, 3. AHHC
SELECT 
	Row_Number() OVER (ORDER BY [string] COLLATE Czech_BIN), [string] 
FROM 
	#t;
	
DROP TABLE #t;