Common Relationship Operators In this chapter, we will discuss about the operators which build on relationships. __eq__() The above operator is a many-to-one “equals” comparison. The line of code for this operator is as shown below − s = session.query(Customer).filter(Invoice.invno.__eq__(12)) The equivalent SQL query for the above line of code is − SELECT customers.id AS […]
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SQLAlchemy ORM – Working with Joins Now that we have two tables, we will see how to create queries on both tables at the same time. To construct a simple implicit join between Customer and Invoice, we can use Query.filter() to equate their related columns together. Below, we load the Customer and Invoice entities at […]
Working with Related Objects In this chapter, we will focus on the related objects in SQLAlchemy ORM. Now when we create a Customer object, a blank invoice collection will be present in the form of Python List. c1 = Customer(name = “Gopal Krishna”, address = “Bank Street Hydarebad”, email = “gk@gmail.com”) The invoices attribute of […]