如何通过 python SQLAlchemy 中的 substring 订购

Question

I'm using SQLAlchemy for my python script, and I am unable to order the select query in asc order based on a substring column value.

The actual query is this one

books = Book.order_by(Book.id.asc(), Book.title.asc()).all()

but I want to order by a substring of the first 4 digits of the title column.

In SQL language I would do so

SELECT * 
FROM book
ORDER BY id asc, substring(title,0,5) asc;

but in SQLAlchemy?

tnx

Answer 1

You can use the function substr:

from sqlachemy import func
books = Book.order_by(Book.id.asc(), func.substr(Book.title, 1, 4).asc()).all()