sqlalchemy.py

# These are my models (some attributes removed for clarity)

class User(db.Model):

	id = db.Column(db.Integer, primary_key=True)

	# user many-to-many size associations (using link tables)
	sz_shirt_dress_sleeve = db.relationship(
		'SizeKeyShirtDressSleeve', secondary=LinkUserSizeShirtDressSleeve, backref=db.backref('users', lazy='dynamic'))
    
LinkUserSizeShirtDressSleeve = db.Table(
	'link_user_size_shirt_dress_sleeve',
	db.Column('size_id', db.Integer, db.ForeignKey('size_key_shirt_dress_sleeve.id'), primary_key=True),
	db.Column('user_id', db.Integer, db.ForeignKey('user.id'), primary_key=True)
)

class SizeKeyShirtDressSleeve(db.Model):
	id = db.Column(db.Integer, primary_key=True)
	size = db.Column(db.Numeric(4,2))

	def __repr__(self):


'''
I'm writing a view that will generate a page to list all of a User's sizes, AS WELL as all possible sizes (a user can be associated with multiple sizes). Possible sleeve sizes range from 30.0 to 38.0 and incrementing by 0.5. 

For example, say User with ID 1 is associated with sizes 30.0, 30.5, 31.0, and 32.0. I need a query for that user that returns this:

Size	|	UserIsAssociated
--------|-------------------
30.0	|	True
30.5	|	True
31.0	|	True
31.5	|	False
32.0	| 	True
32.5	|	False
33.0	|	False
...
38.0	|	False

I'm certain this must be possible, because I can do it in raw SQL. The SQL query that generates such a table looks like:

SELECT 	
	size, 
   	case 	WHEN link_user_size_shirt_dress_sleeve.size_id IS NOT NULL
   			THEN 'true' ELSE 'false' END AS present
	FROM size_key_shirt_dress_sleeve 
	LEFT JOIN link_user_size_shirt_dress_sleeve
	ON size_key_shirt_dress_sleeve.id = link_user_size_shirt_dress_sleeve.size_id
;

This should (I think) be a combination of outerjoin() and case(), but I've been having significant difficulty.

'''