SQL Window Functions: FIRST_VALUE, LAST_VALUE, NTH_VALUE, and Positional Analytics/Get the first value in each partition
Carry the earliest value across all rows in the partition.
Section: Positional functions
Get the first value in each partition
sql
sql
SELECT customer_id,
order_date,
amount,
FIRST_VALUE(amount) OVER (
PARTITION BY customer_id
ORDER BY order_date
ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
) AS first_order_amount
FROM orders;Explanation
Using the full-partition frame makes intent explicit and avoids surprises.
Learn the surrounding workflow
Compare similar commands or jump into common fixes when this command is part of a bigger troubleshooting path.
Related commands
Same sheet · prioritizing Positional functions
Get the true last value in each partition
Use an explicit full frame with LAST_VALUE.
Compare current value to final partition value
Measure remaining distance to the last value.