By default, the FOR Previous function refers to values from one time period ago. You can customize FOR Previous by adding a second parameter to the function.
For differences between FOR Previous and FOR PreviousPeriod see Functions For Referring to Past Time Periods
SELECT … FOR Previous(…,…)
SELECT metric FOR Previous(time_attribute)
SELECT metric FOR Previous(time_attribute, #periods_ago)
SELECT Revenues FOR Previous(Quarter)
By default, FOR Previous()refers to values from one time period ago. This can be customized by adding a second parameter to the function. For example, you may want to return a revenue value from three quarters ago (see below).
SELECT Revenues FOR Previous(Quarter , 3)
Note how the Previous Qtr column in the table below displays a metric that is linked to the metric values in the Amount column with the FOR Previous( ) function.
Even in cases where metric values are broken across a date attribute of smaller time granularity, the GoodData Platform intelligently calculates FOR Previous(quarter) metric values. In the case illustrated below, each month in a quarter is linked to the corresponding month in the previous quarter.