Add files to database

In most uses of a web application, we will need to have a database where we can retrieve information. This is stored in the form of a SQLite database (db.sqlite3), which is referred in the DATABASES in the settings.py.

The database can either be populated using the Django admin site or directly through the app by loading csv/txt files, as guided below:

Set up

1. Deposit the .csv file in the apps folder, within the files directory (need to create directory).

2. Create a .py script to load the csv file, within management\commands directory (need to create directories).

   An example of the folder structure:

   	isoVisDev/
   	├── manage.py
    └── expression/
    	└── files/
    		└── whole_gene_counts.csv   # deposit this csv file here 
    	├── management/
    		└── commands/
    			└── load_gene_counts.py   # create this script 
        ├── migrations/
        ├── __init__.py
        ├── admin.py
        ├── apps.py
        ├── models.py
        ├── tests.py
        └── views.py
   

   In the load_gene_counts.py script:

   from csv import DictReader   
   from django.core.management import BaseCommand
   
   # Import the model 
   from expression.models import Genecounts
   
   class Command(BaseCommand):
       # Show this when the user types help
       help = "Loads data from whole_genecounts.csv"
   
       def handle(self, *args, **options):
       	            
           # Show this before loading the data into the database
           print("Loading gene counts data")
   
           #Code to load the data into database
           for row in DictReader(open('./expression/files/whole_genecounts.csv')):
               Genecount=Genecounts(sampleID=row['sampleID'], geneName=row['geneName'], counts=row['counts'], group=row['group'], sex = row['sex']) 
               Genecount.save()
       
       def __str__(self):
           return self.title