HAVING vs WHERE in SQL
WHERE filters rows before grouping, while HAVING filters groups after aggregation.
- WHERE happens earlier
- HAVING works on grouped results
- Common with aggregate conditions
HAVING vs WHERE in SQL
Tagged with queries
3 cards
Subquery vs join
Joins combine tables directly, while subqueries nest one query inside another; either can be correct depending on clarity and plan quality.
- Joins are often easier to optimize
- Subqueries can express stepwise logic
- Check the execution plan
Subquery vs join
What are common SQL join types and when do you use them?
Inner joins return matches, outer joins preserve unmatched rows from one or both sides depending on the type.
- INNER for only matches
- LEFT when you need all left rows
- FULL when you need everything from both sides
What are common SQL join types and when do you use them?