Common mistake

SQL: LIMIT Without ORDER BY Gives Unpredictable Rows

With no ORDER BY, the database can return any rows in any order. Always sort before you limit.

The symptom

You want the "top 10" or a quick sample, so you add LIMIT 10. It looks fine until the same query returns different rowson another run, on a different database, or after the table is updated. Your "top" report isn't actually the top of anything.

Not the top: just 10 arbitrary rows

select product_name, price
from products
limit 10

Why it happens

LIMIT keeps the first N rows of the result, but withoutORDER BY, SQL does not promise any particular order. The database returns rows in whatever order is convenient (storage order, parallel scan order, index order), and that can change between runs, versions, and engines.LIMIT then slices that undefined order, so which rows you get is essentially arbitrary.

The fix

Add an ORDER BY that makes "first" mean something. For a real top-N, order by the metric; then LIMIT is meaningful and stable.

Right: a real top 10

select product_name, price
from products
order by price desc
limit 10

If ties matter, add a tiebreaker column so the order is fully deterministic otherwise rows with equal price can still swap places.

Break ties for a stable result

select product_name, price
from products
order by price desc, product_name
limit 10

Also applies to pagination

The same rule governs LIMIT … OFFSET … paging: without a stableORDER BY, page 2 can repeat or skip rows it already showed on page 1. Every paged query needs a deterministic sort.