How to query database by id using SqlAlchemy?

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I need to query a SQLAlchemy database by its id something similar to

User.query.filter_by(username='peter')

but for id. How do I do this? [Searching over Google and SO didn't help]

model sqlalchemy sql python
5 Answers

get() is not as your expected sometimes. If your transaction was done:

>>> session.query(User).get(1)
[SQL]: BEGIN (implicit)
[SQL]: SELECT user.id AS user_id, user.name AS user_name, user.fullname AS user_fullname
FROM user
WHERE user.id = ?
[SQL]: (1,)
<User(u'ed', u'Ed Jones')>

If you are in a transaction, get() will give you the result object in memory without query the database:

>>> session.query(User).get(1)
<User(u'ed', u'Ed Jones')>

better to use this:

>>> session.query(User.name).filter(User.id == 1).first()
[SQL]: SELECT user.name AS user_name
FROM user
WHERE user.id = ?
 LIMIT ? OFFSET ?
[SQL]: (1, 1, 0)
(u'Edwardo',)
user_102676250

If you use tables reflection you might have problems with the solutions given. (The previous solutions here didn't work for me).

What I ended up using was:

session.query(object.__class__).get(id)

(object was retrieved by reflection from the database, this is why you need to use .__class__)

I hope this helps.

user_65984220

First, you should set id as the primary key.
Then you could use the query.get() method to query objects by id which is already the primary key.

Since the query.get() method to query objects by the primary key.
Inferred from Flask-SQLAlchemy documentation

from flask import Flask
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
db = SQLAlchemy()
db.init_app(app)

class User(db.Model):
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key=True)

def test():
    id = 1
    user = User.query.get(id)
user_73606760
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