What do LAG and LEAD let you do without a self join?

Problem Statement

Explanation

LAG peeks backward and LEAD peeks forward along the ordered rows in the same partition. This is perfect for day-over-day changes or trend detection. Because they run inside the same result set, you avoid extra joins and keep the query simpler and faster.

Code Solution

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SELECT day, amount,
       amount - LAG(amount) OVER (ORDER BY day) AS delta
FROM sales_by_day;

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Window Functions & Analytics

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What do LAG and LEAD let you do without a self join?

Problem Statement

Explanation

Code Solution

Practice Sets

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What do LAG and LEAD let you do without a self join?

Problem Statement

Explanation

Code Solution

Practice Sets

Related Questions

Which SQL statement retrieves all columns and rows from a table named employees?

Which clause filters rows before aggregation and affects which rows are grouped?

What is the default sort order when ORDER BY is used without ASC or DESC?

Which construct is commonly used to paginate results in SQL engines like Postgres and MySQL?

Which predicate correctly checks for missing values in standard SQL?

More from SQL & Databases

Master Interviews
Anywhere, Anytime