Compute a per-customer total on every row.
Section: OVER clause fundamentals
Aggregate within a partition
sql
sql
SELECT order_id,
customer_id,
amount,
SUM(amount) OVER (PARTITION BY customer_id) AS customer_total
FROM orders;Explanation
`PARTITION BY` resets the calculation for each logical group.
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Compare similar commands or jump into common fixes when this command is part of a bigger troubleshooting path.
Related commands
Same sheet · prioritizing OVER clause fundamentals
Count all rows without collapsing them
Return total row count on every row.
Assign row numbers inside each partition
Number rows in order within each customer.
Use RANGE for peer-aware frames
Group rows that share the same ordering value.
Exclude the current row from a frame
Compare a row against all earlier rows only.