Joins - The DataJoint Book

We will use the design produced in 004-Design. Please execute that notebook first to define and populate the app schema.

Recall the design¶

The following code connects to the app schema and generates Python classes to access its classes.

import datajoint as dj
schema = dj.Schema('app')
schema.spawn_missing_classes()
dj.Diagram(schema)

Purchase()

Queries with Joins¶

Cross Join¶

Account * AddOn

Account * AddOn & 'sex="F"'

dj.Diagram(schema)

Purchase * AddOn

Purchase * AddOn

@schema
class Person(dj.Manual):
    definition = """
    person_id : int 
    --- 
    full_name : varchar(60)
    """
  
@schema
class Dependent(dj.Manual):
    definition = """
    -> Person
    -> Person.proj(provider_id="person_id")
    """

dj.Diagram(schema)

Person.insert((
    (1, "Bob"),
    (2, "Anne"),
    (3, "Dave"),
    (4, "Carol")
))

Dependent.insert1((2, 1))

Dependent.insert1((3, 1))

Dependent.insert1((4, 2))

Person * Dependent * Person.proj(provider_id="person_id", provider_full_name="full_name")

Queries

Homework 6: Joins and Subqueries

Queries

Joins