Assume only two columns(name and id) are needed from a table. I would code something like below:
session.query(User.id, User.name).all()
But if the column names are dynamic,
def get_data(table, columns):
return session.query(*(getattr(table, column) for column in columns)).all()
But the above one looks ugly. Is there a better recommended way?
You can get use of select():
from sqlalchemy.sql import select
columns = ['id', 'name']
print(session.query(select(from_obj=User, columns=columns)).all())
Hope that helps.
query(User.id, User.name) or are there any differences?
from sqlalchemy.sql import select
Textual column expression 'name' should be explicitly declared with text('name'), or use column('name') for more specificity"
Changed in version 1.4: The select() construct now accepts column arguments positionally, as select(*args). The previous style of select() accepting a list of column elements is now deprecated. See select(), case() now accept positional expressions. docs.sqlalchemy.org/en/14/core/tutorial.html#using-textual-sql
columns = ["id", "name"], then cols = [getattr(MyModel, col) for col in columns], then query = select(*cols)