Tips @ Write a better SQL Code

Things to be remembered while writting a SQL code :

1 - Always use set nocount on.

2 - Avoid the use of Distinct keyword and use Group By.

3 - Avoide the use of Order By clause.

4 - Avoid the use of IN keyword use Exists or inner join.

5 - Avoid the use of NOT IN keyword use NOT Exists.

6 - Dont use the cursor use while loop with the help of identity column.

7 - Select only required field in query not use select *.

8 - In case of dynamic query always use sp_executesql instead of execute.

9 - Avoid use of temp table use table variable or CTE.

10 - Do not use the SP_ prefix with stored procedure name.

11 - Avoid any operation on the fields where possible. Some operations will prevent the use of index on this field even if it exist.
EX: where cast(dtfield as varchar(20)) = @DTval

Regards
Manish