Window Function, Function

Window Function, Function

Oracle is called an analysis function.

Same as Aggregate functions, it is used to calculate the row set! However, for group by reason, only one value is returned for each group. The former can return multiple values in each group.

Syntax: function name (column name) over (SQL item)

If the over parameter is null, all rows are aggregated.

Example: SELECT EmpID, DeptID, PostID, sum (PostID) OVER (partition by DeptID, PostID)
FROM dbo. tbEmps

SELECT ROW_NUMBER () OVER (order by PassportID DESC) AS rowNum

FROM dbo. tbEmps