Float type adding extra digit in database structure

Question

My database structure for a currency table has one row for the value of the currency

I am trying to set it at 1.2000000 but after I do it changes to 1.20000005

This is causing my some grief with some other parts of my code that checks for decimals.

the structure is set to: float(13,8)

Possible duplicate of [How do I work with high precision decimals in PHP](http://stackoverflow.com/questions/8485932/how-do-i-work-with-high-precision-decimals-in-php) — Prune, Jan 05 '16 at 19:47

score 3 · Accepted Answer · edited May 23 '17 at 12:23

3

Change the type in database from float to decimal if You need to hold the value of currency

edited May 23 '17 at 12:23

Community

answered Jan 05 '16 at 19:14

rafwlaz

I thought of that but it was already set to float from when the software was originally developed so I didnt want to change too many things. I changed the amount of decimals to 4 from 8 though and that seems to have fixed it without causing any issue. – Sackling Jan 05 '16 at 19:17
@Sackling in this example yes, but when You try to insert another value the problem will still exists, so changing to decimal is best way I think, you no need to do anytching more just change type – rafwlaz Jan 05 '16 at 19:18
I add that problem is not a database, it's a PHP what makes float numbers "griefed". Changing column to decimal(8,4) in sql will suppress this weirdness. see [link](http://stackoverflow.com/questions/3148937/compare-floats-in-php) – Reloecc Jan 05 '16 at 19:19
1

It's IEEE754 what makes float numbers "griefed" - https://en.wikipedia.org/wiki/Floating_point#Accuracy_problems – Mark Baker Jan 05 '16 at 19:29

1 Answers1