I found that care needs to be taken when using Floats, Doubles, BigDecimal, etc... OpenJPA seemed to work in most cases when I was using existing table definitions but I can't say that OpenJPA always generated the proper tables when using synchronize mappings. One oddity/problem I came across had to do with performing arithmetic inside a select on DB2 (and maybe derby). I don't have my notes infront of me right now, but I will open a JIRA for the problems I found sometime here.
On Thu, Jan 7, 2010 at 11:37 AM, C N Davies <c...@cndavies.com> wrote: > Well I haven't fully tested all possible cases, but my app works to 4 > decimal places so I use the column definition shown below (6 places) and I > do not get rounding issues any more. It was a big problem for me when I > first started using OpenJPA a year or so ago because I am back calculating > tax on low value high qty items. > > Chris > > > -----Original Message----- > From: Daryl Stultz [mailto:da...@6degrees.com] > Sent: Friday, 8 January 2010 12:30 AM > To: users@openjpa.apache.org > Subject: Re: Known issues - Floats and doubles may lose precision when > stored. > > On Thu, Jan 7, 2010 at 6:24 AM, C N Davies <c...@cndavies.com> wrote: > > > I'm no expert on this but I find OpenJPA 1.2.1 works just fine on > > ProgresSQL > > when I use specific notation > > > > @Column(columnDefinition="DOUBLE UNSIGNED",precision=10,scale=6, > > nullable=false) > > private double rate = 0.00; > > > > If I don't use the column definition it's a mess > > > The manual [1] states that columnDefinition, precision, and scale are used > for database creation (DDL generation). I'm wondering if you have the > database column correctly does that prevent precision loss or is there > value > truncation of some kind before going to the database. > > [1] > > http://openjpa.apache.org/builds/1.2.1/apache-openjpa-1.2.1/docs/manual/jpa_ > overview_mapping_column.html<http://openjpa.apache.org/builds/1.2.1/apache-openjpa-1.2.1/docs/manual/jpa_%0Aoverview_mapping_column.html> > > > -- > Daryl Stultz > _____________________________________ > 6 Degrees Software and Consulting, Inc. > http://www.6degrees.com > mailto:da...@6degrees.com > > -- Thanks, Rick
