I've got a class:
class Tag(Base, TimestampMixin):
"""Tags"""
__tablename__ = 'tags'
__table_args__ = {'mysql_engine' : 'InnoDB', 'mysql_charset' : 'utf8' }
id = Column(Integer(11), autoincrement = True, primary_key = True)
tag = Column(String(32), nullable = False, unique = True)
cnt = Column(Integer(11), index = True, nullable = False, default = 1)
def __init__(self, tag):
t = session.query(Tag).filter_by(tag=tag).first()
if t:
self.cnt = t.cnt+1
self.tag = t.tag
else:
self.tag = tag
def __repr__(self):
return "<Tag('%s')>" % (self.tag, )
def __unicode__(self):
return "%s" % (self.tag, )
When adding tag:
tag = Tag('tag')
session.add(tag)
session.commit()
I want it to update existing tag
.
Of course, I could've done this:
tag = session.query(Tag).filter_by(tag='tag').first()
if tag:
tag.cnt++
else:
tag = Tag('tag')
session.add(tag)
session.commit()
but, keeping such logic in Tag
class seems to be more clear - possibly keeps me off of the shotgun surgery.
How do I get there?
I'm pretty new to Python
and SQLAlchemy
, so any additional thoughts on my code will be appreciated.
Thank you.
P.S. SQLAlchemy
is SO GIGANTIC and they don't provide a handy way to do INSERT ... ON DUPLICATE KEY UPDATE
, huh? WOW!
You can try this
def get_or_increase_tag(tag_name):
tag = session.query(Tag).filter_by(tag=tag_name).first()
if not tag:
tag = Tag(tag_name)
else:
tag.cnt += 1
return tag
You can check the link https://stackoverflow.com/search?q=Insert+on+duplicate+update+sqlalchemy