Getting overflow error when executing pl/sql query
One of the selected column value is having a precision beyond the .Net's decimal type. The best way to resolve this issue is to ROUND your column values to a manageable prevision size. Normally I round them to 2 digits of decimal place as I would not need anymore than that, you may want to choose according to your need.
So in short, change your query so that all columns with a higher precision number to be rounded off to the number of decimals you need:
Example:
Select ROUND(final_price, 2) From <your table>should address your problem.