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POcreate new SQLalchemy object fails when referenceing uid
 

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  1. POcreate new SQLalchemy object fails when referenceing uid
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    <p>New python and SQLAlchemy user here (yeah i know :)) anyway, I am trying to create some tables using a user, sensor, and reading table where both user and sensor have a one to many relationship to a reading.</p> <p>My classes are like this:</p> <pre><code>class User(db.Model): __tablename__ = 'user' uid = db.Column(db.Integer, primary_key=True, index=True) firstName = db.Column(db.String(100)) lastName = db.Column(db.String(100)) emailAddress = db.Column(db.String(120), unique=True, index=True) pwHash = db.Column(db.String(256)) userLevel = db.Column(db.Integer()) userAccountType = db.Column(db.Integer()) isUserActive = db.Column(db.Boolean()) isUserLockedOut = db.Column(db.Boolean()) userLastLogin = db.Column(db.DateTime()) lastInvalidLogin = db.Column(db.DateTime()) userCreatedAt = db.Column(db.DateTime()) userConfirmedAt = db.Column(db.DateTime()) userUpdatedAt = db.Column(db.DateTime(), onupdate=datetime.datetime.now()) userAddress = db.relationship('Address', backref='user', lazy='dynamic') userContactMethod = db.relationship('UserContactMethod', backref='user', lazy='dynamic') userSensor = db.relationship('Sensor', backref='user', lazy='dynamic') userReading = db.relationship('Reading', backref='user', lazy='dynamic') deliveryEvents = db.relationship('logSMTPDeliveryEvents', backref='user', lazy='dynamic') class Reading(db.Model): __tablename__ = 'reading' rid = db.Column(db.Integer, primary_key=True) uid = db.Column(db.Integer, db.ForeignKey('user.uid')) sid = db.Column(db.Integer, db.ForeignKey('sensor.sid')) readingTimestamp = db.Column(db.DateTime()) readingLightValue = db.Column(db.Integer) readingLightStatus = db.Column(db.String(6)) readingTemp1 = db.Column(db.Float) readingTemp2 = db.Column(db.Float) readingHumidity = db.Column(db.Float) def __init__(self, uid, sid, readingTimestamp, readingLightValue, readingLightStatus, readingTemp1, readingTemp2, readingHumidity): self.uid = uid self.sid = sid self.readingTimestamp = readingTimestamp self.readingLightValue = readingLightValue self.readingLightStatus = readingLightStatus self.readingTemp1 = readingTemp1 self.readingTemp2 = readingTemp2 self.readingHumidity = readingHumidity </code></pre> <p>So, if I try and create on object like this:</p> <pre><code> newReading = Reading(uid=10, sid=123,readingTimestamp = readingTimestamp, readingLightValue=readingLightValue, readingLightStatus=readingLightStatus, readingTemp1=readingTemp1, readingTemp2=readingTemp2, readingHumidity=readingHumidity) db.session.add(newReading) db.session.commit() </code></pre> <p>Where I hardcode the uid everything works fine. Hoewever if I try and use my query before that like so:</p> <pre><code> userID = db.session.query(User.uid).filter(User.emailAddress == userEmailAddress).first() </code></pre> <p>and then I use the userID variable in my create object like this:</p> <pre><code> newReading = Reading(uid=userID, sid=123,readingTimestamp = readingTimestamp, readingLightValue=readingLightValue, readingLightStatus=readingLightStatus, readingTemp1=readingTemp1, readingTemp2=readingTemp2, readingHumidity=readingHumidity) </code></pre> <p>I get the following error:</p> <pre><code>IntegrityError: (IntegrityError) (1452, 'Cannot add or update a child row: a foreign key constraint fails (`gnomecentral`.`reading`, CONSTRAINT `reading_ibfk_1` FOREIGN KEY (`uid`) REFERENCES `user` (`uid`))') 'INSERT INTO reading (uid, sid, `readingTimestamp`, `readingLightValue`, `readingLightStatus`, `readingTemp1`, `readingTemp2`, `readingHumidity`) VALUES (%s, %s, %s, %s, %s, %s, %s, %s)' ((10L,), 123, datetime.datetime(2013, 9, 14, 14, 48, 7, 684071), 43, '43', 43.0, 43.0, 43.0) </code></pre> <p>Thanks in advance for the help! Craig</p>
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