unexpected output sql server using count - sql-server

Question

I am using sql-server 2012
The query is :
CREATE TABLE TEST ( NAME VARCHAR(20) );
INSERT TEST
( NAME
)
SELECT NULL
UNION ALL
SELECT 'James'
UNION ALL
SELECT 'JAMES'
UNION ALL
SELECT 'Eric';
SELECT NAME
, COUNT(NAME) AS T1
, COUNT(COALESCE(NULL, '')) T2
, COUNT(ISNULL(NAME, NULL)) T3
, COUNT(DISTINCT ( Name )) T4
, COUNT(DISTINCT ( COALESCE(NULL, '') )) T5
, ##ROWCOUNT T6
FROM TEST
GROUP BY Name;
DROP TABLE TEST;
In the result set ther is no 'JAMES' ? (caps)
please tell how this was excluded
expected was Null,james,JAMES,eric

Answer 1

You need to change your Name column collation to Latin1_General_CS_AS which is case sensitive
SELECT NAME COLLATE Latin1_General_CS_AS,
Count(NAME) AS T1,
Count(COALESCE(NULL, '')) T2,
Count(Isnull(NAME, NULL)) T3,
Count(DISTINCT ( Name )) T4,
Count(DISTINCT ( COALESCE(NULL, '') )) T5,
##ROWCOUNT T6
FROM TEST
GROUP BY Name COLLATE Latin1_General_CS_AS;

Answer 2

Use a sensitive case collation like COLLATE Latin1_General_CS_AS.
CREATE TABLE TEST ( NAME VARCHAR(20) COLLATE Latin1_General_CS_AS );

Answer 3

The other people who commented here are correct.
It would be easier for you to understand their meaning if you googled for collation and case sensitivity, but in layman's terms it's like this:
Collation is a little like encoding; It determines how the characters in string columns are interpreted, ordered and compared to one another. Case insensitive means that UPPERCASE / lowercase are considered exactly the same, so for instance 'JAMES', 'james', 'JaMeS' etc would be no different to SQL Server. So when your database has a case-insensitive collation and you then create a table with a column without defining the collation, that column will inherit the default collation used by the database, which is how we arrived here.
You can manually alter a column collation, or define it during a query, but bear in mind that whenever you compare two different columns, you need to assign both of them to use the same collation, or you will get an error. That's why it's good practice to pretty much use the same collation throughout the database barring special query-specific circumstances.
To your question regarding what Latin1_General_CS_AS means, it basically means "Latin1_General" alphabet, the details of which you can check online. The "CS" part means case-sensitive, if it were case-insensitive you would see "CI" instead. The "AS" means accent-sensitivity, and "AI" would mean accent-insensitivity. Basically, whether 'Á' is considered to be equal to 'A', or not.
You can read a lot more about it from the source, here.