How to select data where a field has a min value in MySQL?

this will give you result that has the minimum price on all records.

SELECT *
FROM pieces
WHERE price =  ( SELECT MIN(price) FROM pieces )

• SQLFiddle Demo

This is how I would do it, assuming I understand the question.

SELECT * FROM pieces ORDER BY price ASC LIMIT 1

If you are trying to select multiple rows where each of them may have the same minimum price, then @JohnWoo's answer should suffice.

Basically here we are just ordering the results by the price in ascending order (ASC) and taking the first row of the result.

This also works:

SELECT
  pieces.*
FROM
  pieces inner join (select min(price) as minprice from pieces) mn
  on pieces.price = mn.minprice

(since this version doesn't have a where condition with a subquery, it could be used if you need to UPDATE the table, but if you just need to SELECT i would reccommend to use John Woo solution)