Add documentation for altering populated pipelines

[sreguyal]

Feature Request

Problem

Looking for documentation for the alter command. The relevant page in the DataJoint documentation (Schema Design > Schema Modification > Altering Populated Pipelines) is currently blank.

[kushalbakshi]

Hi @sreguyal, thank you for your patience with this. We're going through a round of updates to our documentation. The draft PR #1197 contains information about this if you're needing to use alter(). Here's the snippet from the documentation that will be most useful for you:

Let's say we have a table Student with the following attributes:

@schema
class Student(dj.Manual):
    definition = """
    student_id: int
    ---
    first_name: varchar(40)
    last_name: varchar(40)
    home_address: varchar(100)
    """

We can modify the table to include a new attribute email:

Student.definition = """
student_id: int
---
first_name: varchar(40)
last_name: varchar(40)
home_address: varchar(100)
email: varchar(100)
"""
Student.alter()

alter() currently does not work for updating primary key attributes.