openspout VS Brick\Math

openspout/openspout: Read and write spreadsheet files (CSV, XLSX and ODS), in a fast and scalable way

There is the openspout fork https://github.com/openspout/openspout

brick/math: Arbitrary-precision arithmetic library for PHP

Use strings. For PHP specifically, the Brick/Math library.

There are excellent wrappers for this like https://github.com/brick/math

https://github.com/brick/math to handle bignumber and operations

In Java and Ruby, BigDecimal is an inbuilt class that can be used. For PHP, you can checkout the Brick Math Library Basically, just find the arbitrary-precision Decimal type/Class/Library in your choice of language. Got another approach, please do let me know in comment section.

I decided to use https://github.com/brick/math and store the amount as a string in the database. My project use NANO, so that's 30 decimal points to keep. Number type column is not the choice at all.

There are many use cases where enums don't need to be backed by a scalar. I'm thinking of brick/math's RoundingMode for example: you use these in code, but never store/serialize them really.

Besides, using an arbitrary-precision library gives you an unlimited number of digits, and, in the case of brick/math, many more rounding modes to choose from. And predictable ones.