CODEWITHSUNDEEP
pythongoogle-app-engineflaskapp-engine-ndb
Tesla0lemon
Tesla0lemon

Reputation: 13

How to query an NDB database by string value

I'm trying to create a user login system with flask-login, however i am having difficulties with querying email addresses using Google's query functions.

I can grab the ID, but since a user wont know their ID when logging in, this isn't very useful.

An overview of what the code excerpt is trying to do (I've hardcoded values for the purpose of getting a proof-of-concept working):

username = '[email protected]'
check database for username
Return true if match is found

In this guide, at 9'48", the user writes (what I assume is) a sqlAlchemy query. What would be the equivalent of this query using Googles NDB query functions?

class User(ndb.Model):
   name = ndb.StringProperty()
   email = ndb.StringProperty()
   password = ndb.StringProperty()

@login_manager.user_loader
def load_user(user_id):
return User.get_by_id(int(user_id))

@app.route('/', methods=['GET', 'POST'])
def testlogin():

#user = User.query(getattr(User, 'email') == '[email protected]')
#login_user(user)



check = '[email protected]'
query = User.query(User.email == check)
#print query
#query = User.query()
#queryuser = User.query().filter(User.email == '[email protected]')

#login_user(queryuser)
checkTable = User.get()
#checkTable.email = check
checkTable_key = checkTable
#query = checkTable_key.get()

print str(checkTable_key)

results = User.query().fetch() #this returns a list / array

#print(results)
#print "query all" + str(queryall)

#for  result in results: 
  #print "query all" + str(result.email) 


return "logged in "

Upvotes: 1

Views: 131

Answers (1)

GAEfan
GAEfan

Reputation: 11360

check = '[email protected]'
query = User.query(User.email == check).get() # this returns the User object, or None if not found

if query:
    return True
else:
    return False

# or try
return (query != None)

# or, just return the User object?

# if you just want to see if the user exists, you should do a keys_only query, which is free:

query = User.query(User.email == check).fetch(1, keys_only=True)

Upvotes: 2

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