SQLAlchemy IN clause
PythonSqlalchemyIn ClausePython Problem Overview
I'm trying to do this query in sqlalchemy
SELECT id, name FROM user WHERE id IN (123, 456)
I would like to bind the list [123, 456]
at execution time.
Python Solutions
Solution 1 - Python
How about
session.query(MyUserClass).filter(MyUserClass.id.in_((123,456))).all()
edit: Without the ORM, it would be
session.execute(
select(
[MyUserTable.c.id, MyUserTable.c.name],
MyUserTable.c.id.in_((123, 456))
)
).fetchall()
select()
takes two parameters, the first one is a list of fields to retrieve, the second one is the where
condition. You can access all fields on a table object via the c
(or columns
) property.
Solution 2 - Python
Assuming you use the declarative style (i.e. ORM classes), it is pretty easy:
query = db_session.query(User.id, User.name).filter(User.id.in_([123,456]))
results = query.all()
db_session
is your database session here, while User
is the ORM class with __tablename__
equal to "users"
.
Solution 3 - Python
An alternative way is using raw SQL mode with SQLAlchemy, I use SQLAlchemy 0.9.8, python 2.7, MySQL 5.X, and MySQL-Python as connector, in this case, a tuple is needed. My code listed below:
id_list = [1, 2, 3, 4, 5] # in most case we have an integer list or set
s = text('SELECT id, content FROM myTable WHERE id IN :id_list')
conn = engine.connect() # get a mysql connection
rs = conn.execute(s, id_list=tuple(id_list)).fetchall()
Hope everything works for you.
Solution 4 - Python
Just wanted to share my solution using sqlalchemy and pandas in python 3. Perhaps, one would find it useful.
import sqlalchemy as sa
import pandas as pd
engine = sa.create_engine("postgresql://postgres:my_password@my_host:my_port/my_db")
values = [val1,val2,val3]
query = sa.text("""
SELECT *
FROM my_table
WHERE col1 IN :values;
""")
query = query.bindparams(values=tuple(values))
df = pd.read_sql(query, engine)
Solution 5 - Python
With the expression API, which based on the comments is what this question is asking for, you can use the in_
method of the relevant column.
To query
SELECT id, name FROM user WHERE id in (123,456)
use
myList = [123, 456]
select = sqlalchemy.sql.select([user_table.c.id, user_table.c.name], user_table.c.id.in_(myList))
result = conn.execute(select)
for row in result:
process(row)
This assumes that user_table
and conn
have been defined appropriately.
Solution 6 - Python
Just an addition to the answers above.
If you want to execute a SQL with an "IN" statement you could do this:
ids_list = [1,2,3]
query = "SELECT id, name FROM user WHERE id IN %s"
args = [(ids_list,)] # Don't forget the "comma", to force the tuple
conn.execute(query, args)
Two points:
- There is no need for Parenthesis for the IN statement(like "... IN(%s) "), just put "...IN %s"
- Force the list of your ids to be one element of a tuple. Don't forget the " , " : (ids_list,)
EDIT Watch out that if the length of list is one or zero this will raise an error!