Using a CASE statement to change the value of a new BigQuery column based finding one specific entry inside a PARTITION

Question

I trying to write some case statements which might change the value of all entries in the call if a particular condition is satisfied INSIDE the partition. Here is the specific

Answer 1

If you are looking for avoiding joins, you can use an aggregated function with Over. something like:

Max(If((Your Condition here),Your value here, Null)) Over( Partition By Your_Partition)

the window functions used to had some performance issues that should have been improved recently. My experience with BQ drives me to prefer Jordan's Join suggestion. But hey, its a fun riddle...