Create DB when executing 'flask run'

code/app/__init__.py

@@ -1,5 +1,10 @@
 from flask import Flask
+from config import Config
+from flask_sqlalchemy import SQLAlchemy
 
 app = Flask(__name__)
+app.config.from_object(Config)
+db = SQLAlchemy(app)
 
-from app import routes
+
+from app import routes, models

code/app/models.py

@@ -0,0 +1,44 @@
+from app import db
+from subprocess import run
+from database.constants import DB_USER, DB_PW, DB_NAME
+
+
+class Glacier(db.Model):
+    uid = db.Column(db.String(5), primary_key=True)
+    country = db.Column(db.String(60))
+    name = db.Column(db.String(60))
+    annual_data = db.relationship("Annual_Data")
+
+    def __init__(self, uid, country, name):
+        self.uid = uid
+        self.country = country
+        self.name = name
+
+
+class Annual_Data(db.Model):
+    __tablename__ = "annual_data"
+    year = db.Column(db.Integer, primary_key=True)
+    uid = db.Column(db.ForeignKey("glacier.uid"), primary_key=True)
+    surface = db.Column(db.Float)
+    length = db.Column(db.Float)
+    elevation = db.Column(db.Float)
+
+    def __init__(self, year, surface, length, elevation):
+        self.year = year
+        self.surface = surface
+        self.length = length
+        self.elevation = elevation
+
+
+class User(db.Model):
+    uid = db.Column(db.Integer, primary_key=True)
+    registration_date = db.Column(
+        db.DateTime, nullable=False, server_default=db.func.now()
+    )
+    username = db.Column(db.String(20), nullable=False, unique=True)
+    password = db.Column(db.String(60))
+
+    def __init__(self, uid, username, password):
+        self.uid = uid
+        self.username = username
+        self.password = password