nara-l

# To add a name to migration files rather than 001_auto_20189084774

python manage.py makemigrations --name DESIRED_NAME appName

# e.g. if app name is `site` and you want to name migration, `new_side_bar`

python manage.py makemigrations --name new_side_bar site

nara-l

# Sometimes you need to determine a model name from an object, before using

# First long approach may work in every version of Django? not tested
import sys
model_obj # let model_obj be the model object ( instance) from some input

model_name_str = type(model_obj).__name__ # this is model name as string, but we need the object to do the 
model_object = getattr(sys.modules[__name__], model_name_str)

# now we can use model object normally

nara-l

`class Blog(models.Model):
    #some attributes

class Entry(models.Model):
    blog = models.ForeignKey(Group, related_name='entries') . # this is a ForeignKey  relationship, not a OneToOneField
    #more attributes
`

nara-l

# funny thing Heroku scheduler has no way of running a task monthly easily, one has to use a command like this:

if [ "$(date +%d)" = 01 ]; then MY_COMMAND; fi

# Run task every monday
if [ "$(date +%u)" = 1 ]; then MY_COMMAND; fi

# Run task every 24th of the year
if [ "$(date +%m)" = 12 ] && [ "$(date +%d)" = 24 ]; then MY_COMMAND; fi

nara-l

python manage.py tenant_command dumpdata --schema="schema-name" app.personalitytypes  > app/fixtures/data.json

# 'app' and 'schema-name' to be replaced with necessary variables

nara-l

# tenary opeartor
foo = test? True: False

# python equivalent with if else on same line
foo = "True" if test else "False"

nara-l

git commit --amend -m "New commit message"

# then
git push --force

# it creates a new message and creates a merge of the branch with itself it appears
# this works assuming no one else did any push

nara-l

function dynamicSort(property) {
    var sortOrder = 1;
    if(property[0] === "-") {
        sortOrder = -1;
        property = property.substr(1);
    }
    return function (a,b) {
        var result = (a[property] < b[property]) ? -1 : (a[property] > b[property]) ? 1 : 0;
        return result * sortOrder;
    }

nara-l

heroku config:set VAR_TO_BE_UPDATED: var_value --app APPNAME 

# VAR_TO_BE_UDPATED : var_value is the key value pair of your .env variable
# APPNAME is the name of the app you want to update

nara-l

# say you want to extend the expiration date for subscription service to 14 days, in postgres you can do that by

update users set expiration_date = expiration_date + interval '14 days'; # users is the table where expiration is stored

# I bet this could work, not tested

update users set expiration_date += interval '14 days';

# you could do so much more with interval > http://www.postgresqltutorial.com/postgresql-interval/