Hibernate version: NHibernate1.2.0Beta2

I have a column in a database of type "real". The data in the database can have a high precision (1.40000001 for example). However, whenever I try to Get a row in that table the value is rounded and I lose precision. 1.40000001 becomes 1.4 which throws off our shipping calculations for some countries. I have tried a multitude of things:

Straight nHibernate Gets
ExecuteScalar with a stored proc
ExecuteNonQuery into a dataset from the stored proc
A raw SELECT statement

The type in the database is "real" the nhibernate auto-generated mapping file has the type set at "single". The .NET class is of course also "single". I have tried changing it to other types such as float, and decimal but the problem still occurs.

I have searched on the forums for ways to get around this rounding issue but didn't find anything.

There are also other properties in the same mapping file of type "decimal" that are getting their full precision on a Get. These columns are alos of a different type than "real" in the database.

example:


Weight comes back with rounded precision whereas RetailPrice comes back with its full precision.

Please help, thanks:)

From BOL:
float and real
Approximate number data types for use with floating point numeric data. Floating point data is approximate; not all values in the data type range can be precisely represented.


In my experience it is a bad idea to use the real data type when storing values that need precise precision, unexpected behavior can and often does occur.
You could try converting the value to a money type in the select statement.

I have tried converting it to a few different types.

I can change the type but it would involve a lot of effort and there are a lot of other applications that are able to get the data with it's full precision without issue. I even have a legacy app that works just like the nhibernate app I'm working on now that doesn't have any issue. It seems like in all my testing it is directly related to nHibernate. Maybe I'm mistaken.

Real in SQL Server is equivalent to Float(24) and it can have a precision of atmost 7 digits.

I created a small table with a real column and tried to insert your value 1.40000001 from the Management Studio and it truncates it to 1.4

You will be better of changing it to more precise data type.

Job Samuel