SQL Server2008 window Calculation

(a) window definition : Refers to a set of rows specified for the user, also known as "Partition." As shown in the window partition. Each class is viewed as a data window with a total of three windows

(ii) Related methods of window calculation

1) over () Usage format: function name (column) over (option)

The over keyword means that a function is treated as a window function instead of an aggregate function. The SQL standard allows all aggregate functions to be used as window-opening functions, using the over keyword to differentiate between the two usages.

(iii) Case studies

(1)

Resources:

1 Zhang Hongju "Sharp SQL", Nineth Chapter

2 "open Window function in brief

3 "over () Use of open window function

SQL Server2008 window Calculation