Add database bits.

depicts/database.py

@@ -0,0 +1,21 @@
+from sqlalchemy import create_engine, func
+from sqlalchemy.orm import scoped_session, sessionmaker
+
+session = scoped_session(sessionmaker())
+
+def init_db(db_url):
+    session.configure(bind=get_engine(db_url))
+
+def get_engine(db_url):
+    return create_engine(db_url, pool_recycle=3600, pool_size=20, max_overflow=40)
+
+def init_app(app, echo=False):
+    db_url = app.config['DB_URL']
+    session.configure(bind=get_engine(db_url, echo=echo))
+
+    @app.teardown_appcontext
+    def shutdown_session(exception=None):
+        session.remove()
+
+def now_utc():
+    return func.timezone('utc', func.now())

depicts/model.py

@@ -0,0 +1,35 @@
+from sqlalchemy.ext.declarative import declarative_base
+from .database import session
+from sqlalchemy.schema import Column, ForeignKey
+from sqlalchemy.types import Integer, String
+from sqlalchemy.orm import column_property, relationship
+from sqlalchemy.ext.associationproxy import association_proxy
+from sqlalchemy.sql.expression import cast
+
+Base = declarative_base()
+Base.query = session.query_property()
+
+class DepictsItem(Base):
+    __tablename__ = 'depicts'
+    item_id = Column(Integer, primary_key=True, autoincrement=False)
+    label = Column(String)
+    description = Column(String)
+    commons = Column(String)
+    count = Column(Integer)
+    qid = column_property('Q' + cast(item_id, String))
+    db_alt_labels = relationship('DepictsItemAltLabel',
+                                 collection_class=set,
+                                 cascade='save-update, merge, delete, delete-orphan',
+                                 backref='item')
+    alt_labels = association_proxy('db_alt_labels', 'alt_label')
+
+class DepictsItemAltLabel(Base):
+    __tablename__ = 'depicts_alt_label'
+    item_id = Column(Integer,
+                     ForeignKey('depicts.item_id'),
+                     primary_key=True,
+                     autoincrement=False)
+    alt_label = Column(String, primary_key=True)
+
+    def __init__(self, alt_label):
+        self.alt_label = alt_label