SQLLAGLEADwindow
What are LAG and LEAD in SQL? Neighbouring rows in a window for beginners
LAG and LEAD return the value from the **previous** or **next** row of a window. Plain words: day-over-day delta, time-to-next-event, price change — tasks that previously required self-joining a table. With tables and common pitfalls.
1 λεπτά ανάγνωσηςSQL · LAG · LEAD · window · tutorial
Εξασκηθείτε σε πραγματικές ασκήσεις
Λύστε ασκήσεις στην εξάσκηση SQL με άμεση βαθμολόγηση και υποδείξεις.
Άνοιγμα εξάσκησης
LAGandLEADare window functions that look at neighbouring rows.LAGreturns the previous row's value,LEADthe next. They unlock day-over-day deltas, time-to-next-event, price changes — all the things that previously required self-joins.This article is currently in Russian. The full English translation is on the way.