JOIN
By Sitraka Forler · Lecturer, Durham Business SchoolUpdated 13 September 2026 About this site
Combines rows from two tables based on a matching condition.
INNER JOIN returns only matching rows. LEFT JOIN returns all left rows plus matches from the right (NULLs for non-matches). Used in finance to combine price data with fundamentals or macro indicators.
Example
SELECT e.ticker, e.close, m.cpi FROM equity_prices e JOIN macro_indicators m ON e.date = m.date;