[odb-users] Re: Self persisting objects?

[Oded Arbel]

Re-correction - apparently it didn't work (I'm not sure why I though
it does), as I get this error during compilation:

libodb-2.0.1\odb\database.ixx(49): error C2440: 'initializing' :
cannot convert from 'model::Employee *' to 'const object_pointer &'


On Wed, Aug 29, 2012 at 9:39 PM, Oded Arbel <oded at geek.co.il> wrote:
> Actually, NM - sorry to bother. My mistake that I didn't include the
> generated employee-odb.hxx. After that fix it works fine.
>
> On Wed, Aug 29, 2012 at 9:13 PM, Oded Arbel <oded at geek.co.il> wrote:
>> Hi guys.
>>
>> I'm trying to write a model class that is self contained - i.e. it
>> includes all business logic to manipulate the ODB API and does not
>> require the application to know ODB to operate it.
>>
>> As part of that, I thought it will be cool (and OOish) to be able to
>> create and persist objects using a simple API like this:
>> Employee *e = new Employee("John","Doe");
>> e->persist();
>>
>> The implementation of Employee::persist() could be pretty trivial
>> (assuming someone knows how to initialize a database connection. I'm
>> going to leave that as an exercise to the user and assume an already
>> inited static field):
>> void Employee::persist() {
>>         odb::transaction t(s_db->begin());
>>         s_db->persist(this);
>>         t.commit();
>> }
>>
>> Unfortunately Visual Studio 10 doesn't like me much and breaks when
>> trying to compile.
>>
>> I've seen database.hxx has a definition for persist(T* o), but the
>> "this" pointer is "const Class*" which won't fit.
>>
>> This is what the compiler has to say (actual class names have been
>> modified to protect the cryptic):
>> ---8<---
>> 1>------ Build started: Project: data-model, Configuration: Debug Win32 ------
>> 1>  employee.cpp
>> 1>c:\XXX\libodb-2.0.1\odb\traits.hxx(103): error C2504:
>> 'odb::access::object_traits<T>' : base class undefined
>> 1>          with
>> 1>          [
>> 1>              T=model::Employee
>> 1>          ]
>> 1>          c:\XXX\data-model\src\employee.cpp(17) : see reference to
>> class template instantiation 'odb::object_traits<T>' being compiled
>> 1>          with
>> 1>          [
>> 1>              T=model::Employee
>> 1>          ]
>> 1>c:\XXX\libodb-2.0.1\odb\traits.hxx(104): error C2146: syntax error :
>> missing ',' before identifier 'pointer_type'
>> 1>c:\XXX\libodb-2.0.1\odb\traits.hxx(104): error C2065: 'pointer_type'
>> : undeclared identifier
>> 1>c:\XXX\libodb-2.0.1\odb\traits.hxx(105): error C2955:
>> 'odb::access::object_factory' : use of class template requires
>> template argument list
>> 1>          c:\XXX\libodb-2.0.1\odb\traits.hxx(17) : see declaration
>> of 'odb::access::object_factory'
>> 1>c:\XXX\libodb-2.0.1\odb\traits.hxx(119): error C2146: syntax error :
>> missing ';' before identifier 'const_pointer_type'
>> 1>c:\XXX\libodb-2.0.1\odb\traits.hxx(119): error C3254:
>> 'odb::object_traits<T>' : class contains explicit override
>> 'const_pointer_type' but does not derive from an interface that
>> contains the function declaration
>> 1>          with
>> 1>          [
>> 1>              T=model::Employee
>> 1>          ]
>> 1>c:\XXX\libodb-2.0.1\odb\traits.hxx(119): error C2838:
>> 'const_pointer_type' : illegal qualified name in member declaration
>> 1>c:\XXX\libodb-2.0.1\odb\traits.hxx(119): error C4430: missing type
>> specifier - int assumed. Note: C++ does not support default-int
>> 1>c:\XXX\libodb-2.0.1\odb\traits.hxx(119): error C2602:
>> 'odb::object_traits<T>::const_pointer_type' is not a member of a base
>> class of 'odb::object_traits<T>'
>> 1>          with
>> 1>          [
>> 1>              T=model::Employee
>> 1>          ]
>> 1>          c:\XXX\libodb-2.0.1\odb\traits.hxx(119) : see declaration
>> of 'odb::object_traits<T>::const_pointer_type'
>> 1>          with
>> 1>          [
>> 1>              T=model::Employee
>> 1>          ]
>> 1>c:\XXX\libodb-2.0.1\odb\traits.hxx(119): error C2868:
>> 'odb::object_traits<T>::const_pointer_type' : illegal syntax for
>> using-declaration; expected qualified-name
>> 1>          with
>> 1>          [
>> 1>              T=model::Employee
>> 1>          ]
>> ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
>> ---8<---
>>
>> Any idea what I'm doing wrong here?
>>
>> --
>> Oded
>
>
>
> --
> Oded



-- 
Oded