3 ms·
SELECT * FROM list ORDER BY pos LIMIT 3 If there's an index on pos, there's no cost to the sort.
by cthor 9y ago
SELECT * FROM list ORDER BY pos LIMIT 3
If there's an index on pos, there's no cost to the sort.
- Svip 9y agoSorry, but that's just one user. Assume we have 1000 users, 800 of which have at least one item in the `items` table. Now I want a full select of those 800 users with their first three to-do items in neat columns next to the user. Your select doesn't do that.
- cthor 9y agoAh, ok, I misread. Yeah, that requires a subquery then, but not because of floats being unsuitabe for sorting, but because you're doing a 1-to-many thingy in a 1-to-1 way by hardcoding 3 columns. It's like writing items[0].text + items[1].text + items[2].text In code to simplify it, instead of items.slice(0,2).map((e) => e.text).concat(''); The former mostly works, but it's definitely not elegant. And you have to be sure the number of items being 3 is set in stone.