One of my blog reader have asked a query on SQL Server query execution order. Thought of writing an article on the same. 

 select * from Student where id< 5000 group by studentID having 
subjectid=10 order by student name


Here is the order of execution for your select statement. 
 
FROM --; Which Primary table 

ON --; On which column to join 


JOIN --;With which table, you want to join 

WHERE --; what are 
the conditions to filter the record 

GROUP BY --; on what basis, you want 
to group. 

WITH CUBE or WITH ROLLUP --; Show the data in the form of 
knowledge cubes. 

HAVING --; Another filter criteria 

SELECT --; 
Get the data 

DISTINCT --; Remove duplicates 

ORDER BY --; Display 
in this order 

TOP --; Display only this much.

That's really awesome processing of your query. My only concern is, why we are grouping the data afterwards we are having another filter criteria like having. May be having can be placed front before grouping it.

Anyway, I will put this question to Microsoft.

For our example, 

 select * from Student where id < 5000 group by studentID having 
subjectid=10 order by student name

The order of execution is, 
 from --;where ---; group by --;having -- select -- Order by

Cheers,

Venkatesan prabu .J

http://venkattechnicalblog.blogspot.com/

http://www.kaashivinfotech.com/