Power Platform Community Forum Thread Details

現象
型：numeric(19,1)
333,333,333,333,333,333.3 を Power BI に取り込むと、
BI 上では
333,333,333,333,333,000.0として表示されます。
原因
Power BI の数値型は倍精度浮動小数点（IEEE 754）であり、
有効桁数は約 15 桁に制限されている。
本数値は整数部が 18 桁＋小数 1 桁であり、
有効桁数を超えるため、丸め／精度落ちが発生する。
補足確認
文字列型として扱った場合は
　333,333,333,333,333,333.3 と正しく表示されます。
ただし、文字列型では SUM、除算等の数値計算が難しい。
課題
有効桁数を超える大桁数の数値について、集計（SUM）や除算などの計算を行うためには数値型が必要であるが、数値型で扱う場合、Power BI の仕様上、丸め／精度落ちを回避できない。表示精度と計算精度を同時に満たすことができない。

問い合わせ内容：

上記のような数字が丸められる事象を解決する方法を教えていただきたい。

Categories:

Microsoft Dataverse with Power Apps

Hi @明門-27010521-0

This should really go over to the Fabric side as it doesn't have anything to do with Power Platform.

Let me say that you are correct, Power BI will not resolve your issue, not at least using DAX and not storing it as any type of number. Fabric could but that's another discussion due to the options we would have to get the data their and processed and bla bla.

You are going to have to store it as a string in power bi, no other way around it, zippo.

You are going to have to NOT use dax due to the fact that it will use the internals of Power BI which will round how you do not want.

I do not know the visual, or the background on using the data, so you are going to have to use Power Query (M specifically) directly to resolve the value into what you want and store it as a string. Now there are other options and trying to explain them al here are much for this side of the fence, versus the Power BI + Fabric Community where this should go.

My answer I believe is what you will find over there anyway, but please post over here

Power BI forums - Microsoft Fabric Community

If these suggestions help resolve your issue, Please consider Marking the answer as such and also maybe a like.

Thank you!
Sincerely, Michael Gernaey