mysql,How to save rounded numbers into longtext field?

Question

I have done this calculation:

$number = round(count($exc)/ count($grades),2,PHP_ROUND_HALF_UP);

When save,I have to save it into a field of an existing table which is a longtext type. The numbers got saved but become very long, something like 0.200000000000000011102230246251565404236316680908203125 I think this might cause extra db storage. When I query the numbers, they are still rounded as 2 digital. So, that's an extra converting job. I would like to learn how to save those numbers as rounded number?

Why would you want to store a number as a longtext field? — Madara's Ghost
– Madara's Ghost, Commented Aug 11, 2012 at 8:05
Why are you using a textual type to store numerical data? MySQL has a number of numeric datatypes (INT, NUMERIC, FLOAT, etc), why not use one of those? Using the wrong type for the data you're storing at best robs you of flexibility and at worst will result in incorrect results for SQL operations. You will not get the items back in the order you expect if you try sorting them, for example — GordonM
– GordonM, Commented Aug 11, 2012 at 8:06
because I have to save it into an existing table which is not for me to re-design. — Jenny
– Jenny, Commented Aug 11, 2012 at 8:06

Community · Accepted Answer · 2023-11-17 19:59:20Z

0

You can use PHP sprintf function coupled with format specifier like so:

$number = sprintf("%.3f", round(count($exc)/ count($grades),2,PHP_ROUND_HALF_UP));

If you need more info about that take a look at sprintf PHP documentation here https://www.php.net/manual/en/function.sprintf.php .

edited Nov 17, 2023 at 19:59

CommunityBot

11 silver badge

answered Aug 11, 2012 at 8:08

Giova

2,0151 gold badge21 silver badges29 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

mysql,How to save rounded numbers into longtext field?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related