SQL rounding last zeros I need to store the exact value of a decimal:

For example 0.00500 and 0.0050. 

If I use decimal (10, 5), I receive 0.00500 every time. If I enter 0.0050, I still get 0.00500
There aren't any great answers here. 

I don't know of any commercial database systems that store trailing zeros after the decimal, as these are considered insignificant to meaning. 

However, in scientific measurement, those zeros can be significant, and knowing if something is 0.05 or 0.050000 is a major difference in precision of measurement. 

One option is to store your number as a string/varchar value. This gets icky because now you have to do extra work to protect someone from saving a non-numeric value there.  That's more work for you, and more work for the database every time a value is stored. You can add a check constraint and use TRY_CONVERT() but in my opinion, this is trying to cram a numeric peg into a string hole, and that isn't quite right from a data model perspective. 

A better option might be to simply store your measurement/value in a decimal column, then also store the precision in a separate integer column. When you insert your decimal value of 0.050000, you store 6 as your precision in a separate column. Then, when you consume the data later, your query will return a decimal value of 0.05, and precision 6 ... Which is exactly the data you need to know the original value is 0.050000. Here, there is still some extra work on maintaining your precision column, and it will need to be considered carefully on display (everywhere, including reporting), and in the case of maintaining scientific measurement you'll need to determine significant digits manually when performing math operations.