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.

2026. g. 8. maijs1 min lasīšanaSQL · LAG · LEAD · window · tutorial

LAG and LEAD are window functions that look at neighbouring rows. LAG returns the previous row's value, LEAD the 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.

Praktizējies ar reāliem uzdevumiem

Risini uzdevumus SQL trenažierī ar tūlītēju novērtēšanu un padomiem.

Atvērt trenažieri