<p dir="auto"><strong>Migrated issue, originally created by Anonymous</strong></p>
<p dir="auto">A user has run the unit tests and is confused that many of them fail when running with the default SQLite database.  in theory it would be nice for every single unit test to check against the current database engine and to not run if it is known that the engine does not support a given operation.</p>
<p dir="auto">(omitting unit test output, descriptions follow)</p>
<p dir="auto"><strong>Migrated issue, originally created by Michael Bayer (<a href="https://github.com/zzzeek">@zzzeek</a>)</strong></p>
<p dir="auto">because an inheritance relationship copies the properties from the base mapper to the child mapper at construction time, an add_property on the base mapper fails to propigate to the child mapper.  this is most apparent when creating a backref against the base mapper:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="        content_type = Table('content_type', engine, 
            Column('id', Integer, primary_key=True)
            )
        content = Table('content', engine,
            Column('id', Integer, primary_key=True),
            Column('content_type_id', Integer, ForeignKey('content_type.id'))
            )
        product = Table('product', engine, 
            Column('id', Integer, ForeignKey('content.id'), primary_key=True)
        )
        class ContentType(object): pass
        class Content(object): pass
        class Product(Content): pass

        # this test fails currently
        contents = mapper(Content, content)
        products = mapper(Product, product, inherits=contents)
        content_types = mapper(ContentType, content_type, properties={
            'content':relation(contents, backref='contenttype')
        })
        p = Product()
        p.contenttype = ContentType()"><pre class="notranslate"><code class="notranslate">        content_type = Table('content_type', engine, 
            Column('id', Integer, primary_key=True)
            )
        content = Table('content', engine,
            Column('id', Integer, primary_key=True),
            Column('content_type_id', Integer, ForeignKey('content_type.id'))
            )
        product = Table('product', engine, 
            Column('id', Integer, ForeignKey('content.id'), primary_key=True)
        )
        class ContentType(object): pass
        class Content(object): pass
        class Product(Content): pass

        # this test fails currently
        contents = mapper(Content, content)
        products = mapper(Product, product, inherits=contents)
        content_types = mapper(ContentType, content_type, properties={
            'content':relation(contents, backref='contenttype')
        })
        p = Product()
        p.contenttype = ContentType()
</code></pre></div>