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by jrjames83 3442 days ago
Best way is to see it in action and experiment. A few videos I made (b and c relate to common queries written for BI or CLTV stuff).

a) row_number over() and partition: in the abstract: https://www.youtube.com/watch?v=-X3eIyZV728

b) applied to customer value analysis: https://www.youtube.com/watch?v=iHxJvF0tZOA

c) applied to time differences (also uses materials from b above) https://www.youtube.com/watch?v=5f8tF4U70Ic

After a while you can write these from scratch and they generally work the 1st or 2nd time, but it takes lots of trial and error at first when setting up the partition and ordering clause within the OVER() expression.