What's the best data type to store data of a bank?

Question

I was wondering what's the best data type for transaction amounts (in euro) of a bank ? Example : The person "A" sends 120.59 euros to "B"

What's the best data type to store this data (120.59) in a database ? the transaction amount is positive, 2 digits after the decimal, and it will be used in calculations after (sum of amounts, averages, variance and standard-deviations...etc). Is it okey to use REAL ? DECIMAL is ok ?

Presumably, https://www.postgresql.org/docs/9.1/datatype-money.html — Blorgbeard, Jul 10 '19 at 18:16
@Blorgbeard: [do **not** use the money type](https://wiki.postgresql.org/wiki/Don%27t_Do_This#Don.27t_use_money) — , Jul 10 '19 at 18:16
No, I'm wrong: https://stackoverflow.com/questions/15726535/postgresql-which-datatype-should-be-used-for-currency — Blorgbeard, Jul 10 '19 at 18:17
Oops, forgot I have a sql hammer. @a_horse is the dupe appropriate? — Blorgbeard, Jul 10 '19 at 18:18

score 2 · Accepted Answer · answered Jul 10 '19 at 18:17

You do not want to store monetary amounts using floating point numbers.

You want to store them using fixed point -- that is numeric/decimal. For your example, it would be something like numeric(10, 2). However, you might want fractions of a cent for some reason, so larger precision and scale such as numeric(20, 4) is a good idea.

What's the best data type to store data of a bank?

1 Answers1