Split Instructor model to be OneToOne with new Person model¶
Just as a thought experiment, let’s decide that we want a generic Person model. For the time being, this model will be one-to-one with an Instructor. Let’s assume that our production database has live data in it that we don’t want to break
We want to:
- Create the new Model, Serializer, and Views.
- Make the new migration and customize it
to fix our data, moving
Instructor.nametoPerson.nameand add a relationship fromInstructorto thatPerson. - Update our test fixtures to reflect the changes, including migrating forward and backward.
- Finally, be fairly confident that this will run on our production database.
New Person models, serializers, views¶
As we did previously when we added Instructor, let’s create the new stuff and check it all in as one git commit. We’ll see why in a second.
Custom Person migration¶
(env) django-training$ ./manage.py makemigrations
Migrations for 'myapp':
myapp/migrations/0006_auto_20181205_1804.py
- Create model Person
- Change Meta options on instructor
- Remove field name from instructor
- Add field person to instructor
We customize the migration by renaming it from the auto name and:
- Move adding the new
Instructor.personOneToOneField up to the top. - Add Python code to move the
Instructor.namefield intoPerson.nameand vice-versa.
(env) django-training$ mv myapp/migrations/0006_auto_20181205_1804.py myapp/migrations/0006_person.py
# Generated by Django 2.1.3 on 2018-12-05 18:04
# modified to move instructor.name into person.name
from django.db import migrations, models
import django.db.models.deletion
import uuid
class Migration(migrations.Migration):
dependencies = [
('myapp', '0005_auto_20181205_1532'),
]
def instr_name_to_person(apps, schema_editor):
"""
Move the instructor name to person model.
Creates a new person instance for each instructor.
"""
Person = apps.get_model('myapp', 'Person')
Instructor = apps.get_model('myapp', 'Instructor')
for row in Instructor.objects.all():
row.person = Person(name=row.name)
row.save(update_fields=['person'])
row.person.save()
def person_name_to_instr(apps, schema_editor):
"""
Move the person name to instructor model.
"""
Person = apps.get_model('myapp', 'Person')
Instructor = apps.get_model('myapp', 'Instructor')
for row in Instructor.objects.all():
row.name = row.person.name
row.save(update_fields=['name'])
operations = [
migrations.CreateModel(
name='Person',
fields=[
('id', models.UUIDField(default=uuid.uuid4, editable=False, help_text='globally unique id (UUID4)', primary_key=True, serialize=False)),
('effective_start_date', models.DateField(blank=True, default=None, help_text='date when this model instance becomes valid', null=True)),
('effective_end_date', models.DateField(blank=True, default=None, help_text='date when this model instance becomes invalid', null=True)),
('last_mod_user_name', models.CharField(default=None, help_text='who last modified this instance', max_length=80, null=True)),
('last_mod_date', models.DateField(auto_now=True, help_text='when they modified it.')),
('name', models.CharField(db_column='person_name', max_length=100, unique=True)),
],
options={
'verbose_name_plural': 'people',
'ordering': ['name'],
},
),
migrations.AddField(
model_name='instructor',
name='person',
field=models.OneToOneField(default=None, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='people', to='myapp.Person'),
),
migrations.RunPython(
code=instr_name_to_person,
reverse_code=person_name_to_instr,
),
migrations.AlterModelOptions(
name='instructor',
options={'ordering': ['id']},
),
migrations.RemoveField(
model_name='instructor',
name='name',
),
]
Now we’ll commit this work:
(env) django-training$ git add myapp training/
(env) django-training$ git status
On branch master
Your branch is ahead of 'origin/master' by 3 commits.
(use "git push" to publish your local commits)
Changes to be committed:
(use "git reset HEAD <file>..." to unstage)
new file: myapp/migrations/0006_person.py
modified: myapp/models.py
modified: myapp/serializers.py
modified: myapp/views.py
modified: training/urls.py
(env) django-training$ git commit -m "add person model"
Update fixtures¶
Our test fixtures currently only work with an older version of our app’s models, so let’s:
- Checkout that older version.
- Start with a fresh sqlite3 database.
- Migrate and load the current fixture data.
- Dump out the new fixture data.
(env) django-training$ git log
commit c085297f67fd586ef9d9f8a027c51c9930ae3c31 (HEAD -> master)
Author: Alan Crosswell <[email protected]>
Date: Wed Dec 5 13:27:48 2018 -0500
add person model
commit d6ee827f7ffbb81772d73ef6d8dc9084fdd4df2b
Author: Alan Crosswell <[email protected]>
Date: Wed Dec 5 10:42:54 2018 -0500
apply migrations forced by help_text
...
(env) django-training$ git checkout d6ee827f7ffbb81772d73ef6d8dc9084fdd4df2b
M docs/conf.py
Note: checking out 'd6ee827f7ffbb81772d73ef6d8dc9084fdd4df2b'.
You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by performing another checkout.
If you want to create a new branch to retain commits you create, you may
do so (now or later) by using -b with the checkout command again. Example:
git checkout -b <new-branch-name>
HEAD is now at d6ee827 apply migrations forced by help_text
(env) django-training$ rm db.sqlite3
(env) django-training$ ./manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, myapp, oauth2_provider, sessions
Running migrations:
Applying contenttypes.0001_initial... OK
Applying auth.0001_initial... OK
Applying admin.0001_initial... OK
Applying admin.0002_logentry_remove_auto_add... OK
Applying admin.0003_logentry_add_action_flag_choices... OK
Applying contenttypes.0002_remove_content_type_name... OK
Applying auth.0002_alter_permission_name_max_length... OK
Applying auth.0003_alter_user_email_max_length... OK
Applying auth.0004_alter_user_username_opts... OK
Applying auth.0005_alter_user_last_login_null... OK
Applying auth.0006_require_contenttypes_0002... OK
Applying auth.0007_alter_validators_add_error_messages... OK
Applying auth.0008_alter_user_username_max_length... OK
Applying auth.0009_alter_user_last_name_max_length... OK
Applying myapp.0001_initial... OK
Applying myapp.0002_auto_20181019_1821... OK
Applying myapp.0003_unique_term_identifier... OK
Applying myapp.0004_instructor... OK
Applying myapp.0005_auto_20181205_1532... OK
Applying oauth2_provider.0001_initial... OK
Applying oauth2_provider.0002_08_updates... OK
Applying oauth2_provider.0003_auto_20160316_1503... OK
Applying oauth2_provider.0004_auto_20160525_1623... OK
Applying oauth2_provider.0005_auto_20170514_1141... OK
Applying oauth2_provider.0006_auto_20171214_2232... OK
Applying sessions.0001_initial... OK
(env) django-training$ rm db.sqlite3
(env) django-training$ ./manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, myapp, oauth2_provider, sessions
Running migrations:
Applying contenttypes.0001_initial... OK
Applying auth.0001_initial... OK
Applying admin.0001_initial... OK
Applying admin.0002_logentry_remove_auto_add... OK
Applying admin.0003_logentry_add_action_flag_choices... OK
Applying contenttypes.0002_remove_content_type_name... OK
Applying auth.0002_alter_permission_name_max_length... OK
Applying auth.0003_alter_user_email_max_length... OK
Applying auth.0004_alter_user_username_opts... OK
Applying auth.0005_alter_user_last_login_null... OK
Applying auth.0006_require_contenttypes_0002... OK
Applying auth.0007_alter_validators_add_error_messages... OK
Applying auth.0008_alter_user_username_max_length... OK
Applying auth.0009_alter_user_last_name_max_length... OK
Applying myapp.0001_initial... OK
Applying myapp.0002_auto_20181019_1821... OK
Applying myapp.0003_unique_term_identifier... OK
Applying myapp.0004_instructor... OK
Applying myapp.0005_auto_20181205_1532... OK
Applying oauth2_provider.0001_initial... OK
Applying oauth2_provider.0002_08_updates... OK
Applying oauth2_provider.0003_auto_20160316_1503... OK
Applying oauth2_provider.0004_auto_20160525_1623... OK
Applying oauth2_provider.0005_auto_20170514_1141... OK
Applying oauth2_provider.0006_auto_20171214_2232... OK
Applying sessions.0001_initial... OK
(env) django-training$ ./manage.py loaddata myapp/fixtures/testcases.yaml
Installed 34 object(s) from 1 fixture(s)
(env) django-training$ git checkout master
M docs/conf.py
Previous HEAD position was d6ee827 apply migrations forced by help_text
Switched to branch 'master'
Your branch is ahead of 'origin/master' by 4 commits.
(use "git push" to publish your local commits)
(env) django-training$ ./manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, myapp, oauth2_provider, sessions
Running migrations:
Applying myapp.0006_person... OK
(env) django-training$ sqlite3 db.sqlite3
-- Loading resources from /Users/ac45/.sqliterc
SQLite version 3.24.0 2018-06-04 14:10:15
Enter ".help" for usage hints.
sqlite> select * from myapp_instructor;
id effective_start_date effective_end_date last_mod_user_name last_mod_date person_id
-------------------------------- -------------------- ------------------ ------------------ ------------- --------------------------------
0a879dc663d44a79aae663ee2b379b32 2018-11-12 4a64f7fa0c47402c907b83fa339afc64
1b3b7d1a7eb543a2941fc18364013f9c 2018-11-12 b3e1d967e8864797aaf28dbe669ceb07
40678ab507fa4c93a680bceda8a34735 2018-11-12 8c1bf6eb810e40608a41e87e9732e545
4baaf8fa98324732a1ddee7bc5e58c21 2018-11-12 a060bdbe6a3f49a08172ad89742b82c4
aae87c7f851544cfb1c779c6f81cc5c5 2018-11-12 7fe24e43eceb4d0394e773ef73ffccb0
sqlite> select * from myapp_person;
id effective_start_date effective_end_date last_mod_user_name last_mod_date person_name
-------------------------------- -------------------- ------------------ ------------------ ------------- ------------------
b3e1d967e8864797aaf28dbe669ceb07 2018-12-05 Alexander Hamilton
7fe24e43eceb4d0394e773ef73ffccb0 2018-12-05 Gouverneur Morris
4a64f7fa0c47402c907b83fa339afc64 2018-12-05 John Jay
a060bdbe6a3f49a08172ad89742b82c4 2018-12-05 Robert Livingston
8c1bf6eb810e40608a41e87e9732e545 2018-12-05 Samuel Johnson
sqlite>
(env) django-training$ ./manage.py dumpdata myapp --format yaml >myapp/fixtures/testcases.yaml
(env) django-training$ git diff myapp
diff --git a/myapp/fixtures/testcases.yaml b/myapp/fixtures/testcases.yaml
index 9572763..8dd3672 100644
--- a/myapp/fixtures/testcases.yaml
+++ b/myapp/fixtures/testcases.yaml
@@ -55,7 +55,6 @@
last_mod_date: 2018-08-03, school_bulletin_prefix_code: B, suffix_two: '00', subject_area_code: BUEC,
course_number: '72074', course_identifier: BUEC7255B, course_name: 'FinTech: Consumer
Financial Se', course_description: 'FinTech: Consumer Financial Se'}
-# this course has no courseterm children:
- model: myapp.course
pk: 04893b8f-0cbe-4e09-b8e6-17a4745900c1
fields: {effective_start_date: null, effective_end_date: null, last_mod_user_name: loader,
@@ -123,6 +122,11 @@
fields: {effective_start_date: null, effective_end_date: null, last_mod_user_name: loader,
last_mod_date: 2018-08-03, term_identifier: 20181ACCT7022B, audit_permitted_code: 0,
exam_credit_flag: false, course: 016659e9-e29f-49b4-b85d-d25da0724dbb}
+- model: myapp.courseterm
+ pk: 48a7ab4f-35d7-4004-97b2-2a95626dd25a
+ fields: {effective_start_date: null, effective_end_date: null, last_mod_user_name: admin,
+ last_mod_date: 2018-12-05, term_identifier: 20181COMS3109W, audit_permitted_code: 0,
+ exam_credit_flag: false, course: null}
- model: myapp.courseterm
pk: 52cc86dd-7a78-48b8-a6a5-76c1fc7fc9be
fields: {effective_start_date: null, effective_end_date: null, last_mod_user_name: loader,
@@ -153,12 +157,26 @@
fields: {effective_start_date: null, effective_end_date: null, last_mod_user_name: loader,
last_mod_date: 2018-08-03, term_identifier: 20181AMST3704X, audit_permitted_code: 0,
exam_credit_flag: false, course: 01ca197f-c00c-4f24-a743-091b62f1d500}
-# a coursterm item that doesn't refers back to a parent course:
-- model: myapp.courseterm
- pk: 48a7ab4f-35d7-4004-97b2-2a95626dd25a
- fields: {effective_start_date: null, effective_end_date: null, last_mod_user_name: admin,
- last_mod_date: 2018-12-05, term_identifier: 20181COMS3109W, audit_permitted_code: 0,
- exam_credit_flag: false, course: null}
+- model: myapp.person
+ pk: 4a64f7fa-0c47-402c-907b-83fa339afc64
+ fields: {effective_start_date: null, effective_end_date: null, last_mod_user_name: null,
+ last_mod_date: 2018-12-05, name: John Jay}
+- model: myapp.person
+ pk: 7fe24e43-eceb-4d03-94e7-73ef73ffccb0
+ fields: {effective_start_date: null, effective_end_date: null, last_mod_user_name: null,
+ last_mod_date: 2018-12-05, name: Gouverneur Morris}
+- model: myapp.person
+ pk: 8c1bf6eb-810e-4060-8a41-e87e9732e545
+ fields: {effective_start_date: null, effective_end_date: null, last_mod_user_name: null,
+ last_mod_date: 2018-12-05, name: Samuel Johnson}
+- model: myapp.person
+ pk: a060bdbe-6a3f-49a0-8172-ad89742b82c4
+ fields: {effective_start_date: null, effective_end_date: null, last_mod_user_name: null,
+ last_mod_date: 2018-12-05, name: Robert Livingston}
+- model: myapp.person
+ pk: b3e1d967-e886-4797-aaf2-8dbe669ceb07
+ fields: {effective_start_date: null, effective_end_date: null, last_mod_user_name: null,
+ last_mod_date: 2018-12-05, name: Alexander Hamilton}
- model: myapp.instructor
pk: 0a879dc6-63d4-4a79-aae6-63ee2b379b32
fields:
@@ -166,7 +184,7 @@
effective_end_date: null
last_mod_user_name: null
last_mod_date: 2018-11-12
- name: John Jay
+ person: 4a64f7fa-0c47-402c-907b-83fa339afc64
course_terms: [39ca7b38-f273-4fa3-9494-5a422780aebd, 00d14ddb-9fb5-4cff-9954-d52fc33217e7]
- model: myapp.instructor
pk: 1b3b7d1a-7eb5-43a2-941f-c18364013f9c
@@ -175,7 +193,7 @@
effective_end_date: null
last_mod_user_name: null
last_mod_date: 2018-11-12
- name: Alexander Hamilton
+ person: b3e1d967-e886-4797-aaf2-8dbe669ceb07
course_terms: []
- model: myapp.instructor
pk: 40678ab5-07fa-4c93-a680-bceda8a34735
@@ -184,7 +202,7 @@
effective_end_date: null
last_mod_user_name: null
last_mod_date: 2018-11-12
- name: Samuel Johnson
+ person: 8c1bf6eb-810e-4060-8a41-e87e9732e545
course_terms: [00d14ddb-9fb5-4cff-9954-d52fc33217e7, 00290ba0-ebae-44c0-9f4b-58a5f27240ed]
- model: myapp.instructor
pk: 4baaf8fa-9832-4732-a1dd-ee7bc5e58c21
@@ -193,7 +211,7 @@
effective_end_date: null
last_mod_user_name: null
last_mod_date: 2018-11-12
- name: Robert Livingston
+ person: a060bdbe-6a3f-49a0-8172-ad89742b82c4
course_terms: []
- model: myapp.instructor
pk: aae87c7f-8515-44cf-b1c7-79c6f81cc5c5
@@ -202,5 +220,5 @@
effective_end_date: null
last_mod_user_name: null
last_mod_date: 2018-11-12
- name: Gouverneur Morris
+ person: 7fe24e43-eceb-4d03-94e7-73ef73ffccb0
course_terms: [00d14ddb-9fb5-4cff-9954-d52fc33217e7]
Run tox to make sure our test cases still work.
(env) django-training$ tox
It’s probably a good idea to update the test cases for the changed models….
Make sure reverse migrations work¶
Let’s also test the reverse migration to make sure we got that right. This works fine if there’s no data loaded, but fails if there is data to migrate:
(env) django-training$ DJANGO_DEBUG=true ./manage.py migrate myapp 0005_auto_20181205_1532
2018-12-05 20:58:16,667 (0.000)
SELECT name, type FROM sqlite_master
WHERE type in ('table', 'view') AND NOT name='sqlite_sequence'
ORDER BY name; args=None
2018-12-05 20:58:16,668 (0.000) SELECT "django_migrations"."app", "django_migrations"."name" FROM "django_migrations"; args=()
2018-12-05 20:58:16,669 (0.000)
SELECT name, type FROM sqlite_master
WHERE type in ('table', 'view') AND NOT name='sqlite_sequence'
ORDER BY name; args=None
2018-12-05 20:58:16,669 (0.000) SELECT "django_migrations"."app", "django_migrations"."name" FROM "django_migrations"; args=()
Operations to perform:
Target specific migration: 0005_auto_20181205_1532, from myapp
Running migrations:
2018-12-05 20:58:16,685 (0.000)
SELECT name, type FROM sqlite_master
WHERE type in ('table', 'view') AND NOT name='sqlite_sequence'
ORDER BY name; args=None
Rendering model states... DONE
2018-12-05 20:58:16,704 (0.000) PRAGMA foreign_keys = OFF; args=None
2018-12-05 20:58:16,704 (0.000) BEGIN; args=None
2018-12-05 20:58:16,719 ALTER TABLE "myapp_instructor" RENAME TO "myapp_instructor__old"; (params ())
2018-12-05 20:58:16,720 (0.001) ALTER TABLE "myapp_instructor" RENAME TO "myapp_instructor__old"; args=()
2018-12-05 20:58:16,720 CREATE TABLE "myapp_instructor" ("id" char(32) NOT NULL PRIMARY KEY, "effective_start_date" date NULL, "effective_end_date" date NULL, "last_mod_user_name" varchar(80) NULL, "last_mod_date" date NOT NULL); (params None)
2018-12-05 20:58:16,720 (0.000) CREATE TABLE "myapp_instructor" ("id" char(32) NOT NULL PRIMARY KEY, "effective_start_date" date NULL, "effective_end_date" date NULL, "last_mod_user_name" varchar(80) NULL, "last_mod_date" date NOT NULL); args=None
2018-12-05 20:58:16,720 INSERT INTO "myapp_instructor" ("id", "effective_start_date", "effective_end_date", "last_mod_user_name", "last_mod_date") SELECT "id", "effective_start_date", "effective_end_date", "last_mod_user_name", "last_mod_date" FROM "myapp_instructor__old"; (params ())
2018-12-05 20:58:16,721 (0.000) INSERT INTO "myapp_instructor" ("id", "effective_start_date", "effective_end_date", "last_mod_user_name", "last_mod_date") SELECT "id", "effective_start_date", "effective_end_date", "last_mod_user_name", "last_mod_date" FROM "myapp_instructor__old"; args=()
2018-12-05 20:58:16,721 DROP TABLE "myapp_instructor__old"; (params ())
2018-12-05 20:58:16,721 (0.000) DROP TABLE "myapp_instructor__old"; args=()
2018-12-05 20:58:16,722 ALTER TABLE "myapp_instructor" RENAME TO "myapp_instructor__old"; (params ())
2018-12-05 20:58:16,722 (0.000) ALTER TABLE "myapp_instructor" RENAME TO "myapp_instructor__old"; args=()
2018-12-05 20:58:16,722 CREATE TABLE "myapp_instructor" ("instr_name" varchar(100) NOT NULL UNIQUE, "id" char(32) NOT NULL PRIMARY KEY, "effective_start_date" date NULL, "effective_end_date" date NULL, "last_mod_user_name" varchar(80) NULL, "last_mod_date" date NOT NULL); (params None)
2018-12-05 20:58:16,722 (0.000) CREATE TABLE "myapp_instructor" ("instr_name" varchar(100) NOT NULL UNIQUE, "id" char(32) NOT NULL PRIMARY KEY, "effective_start_date" date NULL, "effective_end_date" date NULL, "last_mod_user_name" varchar(80) NULL, "last_mod_date" date NOT NULL); args=None
2018-12-05 20:58:16,723 INSERT INTO "myapp_instructor" ("id", "effective_start_date", "effective_end_date", "last_mod_user_name", "last_mod_date", "instr_name") SELECT "id", "effective_start_date", "effective_end_date", "last_mod_user_name", "last_mod_date", NULL FROM "myapp_instructor__old"; (params ())
2018-12-05 20:58:16,723 (0.000) INSERT INTO "myapp_instructor" ("id", "effective_start_date", "effective_end_date", "last_mod_user_name", "last_mod_date", "instr_name") SELECT "id", "effective_start_date", "effective_end_date", "last_mod_user_name", "last_mod_date", NULL FROM "myapp_instructor__old"; args=()
2018-12-05 20:58:16,725 (0.000) PRAGMA foreign_keys = ON; args=None
Unapplying myapp.0006_auto_20181205_2048...Traceback (most recent call last):
File "/Users/alan/src/django-training/env/lib/python3.6/site-packages/django/db/backends/utils.py", line 85, in _execute
return self.cursor.execute(sql, params)
File "/Users/alan/src/django-training/env/lib/python3.6/site-packages/django/db/backends/sqlite3/base.py", line 296, in execute
return Database.Cursor.execute(self, query, params)
sqlite3.IntegrityError: NOT NULL constraint failed: myapp_instructor.instr_name
It’s clear what the problem is (with database backend debugging turned on).
instructor.name can’t be NULL but the steps used to reverse the migration do in fact make it NULL:
INSERT INTO "myapp_instructor" ("id", "effective_start_date", "effective_end_date", "last_mod_user_name", "last_mod_date", "instr_name") SELECT "id", "effective_start_date", "effective_end_date", "last_mod_user_name", "last_mod_date", NULL FROM "myapp_instructor__old"
It appears that this is a
documented restricition of RemoveField
however, here’s a simple workaround: Simply convert the instructor.name field to NULLable with a default value
as the first step in the migration. This will then reverse back to allow the preceding INSERT to work and then
further reverse to make the name non-NULLable.
diff --git a/myapp/migrations/0006_person.py b/myapp/migrations/0006_person.py
index f25f676..f150ac8 100644
--- a/myapp/migrations/0006_person.py
+++ b/myapp/migrations/0006_person.py
@@ -35,6 +35,12 @@ class Migration(migrations.Migration):
row.save(update_fields=['name'])
operations = [
+ # temporarily alter instructor.name to be nullable to enable reversing the migration.
+ migrations.AlterField(
+ model_name='instructor',
+ name='name',
+ field=models.CharField(db_column='instr_name', max_length=100, unique=True, null=True, default=None)
+ ),
migrations.CreateModel(
name='Person',
fields=[
(env) django-training$ ./manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, myapp, oauth2_provider, sessions
Running migrations:
Applying myapp.0006_person... OK
(env) django-training$ sqlite3 db.sqlite3
-- Loading resources from /Users/ac45/.sqliterc
SQLite version 3.24.0 2018-06-04 14:10:15
Enter ".help" for usage hints.
sqlite> select * from myapp_instructor;
id effective_start_date effective_end_date last_mod_user_name last_mod_date person_id
-------------------------------- -------------------- ------------------ ------------------ ------------- --------------------------------
0a879dc663d44a79aae663ee2b379b32 2018-11-12 fc313d67f29c40e48664481a6b7a3dae
1b3b7d1a7eb543a2941fc18364013f9c 2018-11-12 3df528fed5064878a423983a2181bf3d
40678ab507fa4c93a680bceda8a34735 2018-11-12 7077ee3c840c4e41a303953142f8a784
4baaf8fa98324732a1ddee7bc5e58c21 2018-11-12 9ded69e493aa4343a0af3bccfbe05c93
aae87c7f851544cfb1c779c6f81cc5c5 2018-11-12 9612c115b96747d98dfa07fe2c0f1313
sqlite> select * from myapp_person;
id effective_start_date effective_end_date last_mod_user_name last_mod_date person_name
-------------------------------- -------------------- ------------------ ------------------ ------------- ------------------
3df528fed5064878a423983a2181bf3d 2018-12-06 Alexander Hamilton
9612c115b96747d98dfa07fe2c0f1313 2018-12-06 Gouverneur Morris
fc313d67f29c40e48664481a6b7a3dae 2018-12-06 John Jay
9ded69e493aa4343a0af3bccfbe05c93 2018-12-06 Robert Livingston
7077ee3c840c4e41a303953142f8a784 2018-12-06 Samuel Johnson
sqlite>
(env) django-training$ ./manage.py migrate myapp 0005_auto_20181205_1532
Operations to perform:
Target specific migration: 0005_auto_20181205_1532, from myapp
Running migrations:
Rendering model states... DONE
Unapplying myapp.0006_person... OK
(env) django-training$ sqlite3 db.sqlite3
-- Loading resources from /Users/ac45/.sqliterc
SQLite version 3.24.0 2018-06-04 14:10:15
Enter ".help" for usage hints.
sqlite> select * from myapp_person;
Error: no such table: myapp_person
sqlite> select * from myapp_instructor;
instr_name id effective_start_date effective_end_date last_mod_user_name last_mod_date
---------- -------------------------------- -------------------- ------------------ ------------------ -------------
John Jay 0a879dc663d44a79aae663ee2b379b32 2018-11-12
Alexander 1b3b7d1a7eb543a2941fc18364013f9c 2018-11-12
Samuel Joh 40678ab507fa4c93a680bceda8a34735 2018-11-12
Robert Liv 4baaf8fa98324732a1ddee7bc5e58c21 2018-11-12
Gouverneur aae87c7f851544cfb1c779c6f81cc5c5 2018-11-12
sqlite>