<h3>Importing Flask</h3>
<pre class="language-python"><code>from flask import Flask</code></pre>
<h3>Most used import functions</h3>
<p>These are some of the most used import functions by flask developers</p>
<pre class="language-python"><code>from flask import Flask, render_template, redirect, url_for, request</code></pre>
<h3>Boilerplate code</h3>
<p>This is the basic template or barebone structure of a Flask app</p>
<pre class="language-python"><code>from flask import Flask

app = Flask(__name__)

@app.route("/")
def hello_world():
    return "&lt;p&gt;Hello, World!&lt;/p&gt;"

app.run()</code></pre>
<h3>Creating a route</h3>
<p>This is to make different endpoints in our flask app.</p>
<pre class="language-python"><code>@app.route("/")</code></pre>
<h3>Setting Allowed methods</h3>
<p>Used to specify which methods are allowed for a request. Allowing get and post requests on an endpoint.</p>
<pre class="language-python"><code>methods = ['GET', 'POST']</code></pre>
<h3>Re-run while coding</h3>
<p>This is used to automatically rerun the program when the file is saved.</p>
<pre class="language-python"><code>app.run(debug=True)</code></pre>
<h3>Change host</h3>
<p>This is used to change the host.</p>
<pre class="language-python"><code>app.run(host='0.0.0.0')</code></pre>
<h3>Change port</h3>
<p>This is used to change the port.</p>
<pre class="language-python"><code>app.run(port=80)</code></pre>
<h3>Importing SQLAlchemy</h3>
<pre class="language-python"><code>from flask_sqlalchemy import SQLAlchemy</code></pre>
<h3>Database URI</h3>
<p>This is the database's address.</p>
<pre class="language-python"><code>app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://username:password@localhost/db_name' </code></pre>
<p>or&nbsp;</p>
<pre class="language-python"><code>app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///test.db'</code></pre>
<h3>Initialization</h3>
<p>This is used to initialize SQLAlchemy.</p>
<pre class="language-python"><code>db = SQLAlchemy(app)</code></pre>
<p>&lt;|AD|&gt;</p>
<h3>Creating a Model</h3>
<p>Class used to get data from the database and to send data to the database.</p>
<pre class="language-python"><code>class TableName(db.Model): 
    column_1 = db.Column(db.Integer, primary_key=True)
    column_2 = db.Column(db.String(80), nullable=False)
    column_3 = db.Column(db.String(12), nullable=False)</code></pre>
<h3>Get all data - all() method</h3>
<p>This is used to get all the data from the database.</p>
<pre class="language-python"><code>data = ClassName.query.filter_by().all()</code></pre>
<h3>Filtered data - first() method</h3>
<p>This is used to get the first dataset from the list returned by the filter_by function. You can get targetted data by this.</p>
<pre class="language-python"><code>data = ClassName.query.filter_by().first()</code></pre>
<h3>Send/add data to database</h3>
<p>This is used to send/add data to the database.</p>
<pre class="language-python"><code>data_to_send = ClassName(column_1=dataset1, column_2=dataset2, column_3=dataset3) 
db.session.add(data_to_send) 
db.session.commit()</code></pre>
<h3>Delete data from the database</h3>
<p>This is used to delete data from the database.</p>
<pre class="language-python"><code>data_to_send = ClassName(column_1=dataset1, column_2=dataset2, column_3=dataset3)
db.session.delete(data_to_send)
db.session.commit()</code></pre>
<h3>Request method</h3>
<p>This is used to know what request is made (get/post).</p>
<pre class="language-python"><code>request.method</code></pre>
<h3>Render Template</h3>
<p>This is used to pass and render an html file directly.</p>
<pre class="language-python"><code>render_template("file.html")</code></pre>
<h3>Solving FSADeprecationWarning</h3>
<p><code>SQLALCHEMY_TRACK_MODIFICATIONS</code> allows you to disable the modification tracking system using this line:</p>
<pre class="language-python"><code>app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False</code></pre>
<h3>Creating Database files</h3>
<p>This is used to create database files</p>
<pre class="language-python"><code>from yourapplicationname import db 
db.create_all() 
exit()</code></pre>
<h3>Method to return database items</h3>
<p>This is used to return database items.</p>
<pre class="language-python"><code>def __repr__(self) -&gt; str: 
    return f"{self.item}"</code></pre>
<h3>Printing returned content from the method</h3>
<p>This is used to print returned database items.</p>
<pre class="language-python"><code>data = ClassNameWithMethod.query.all() 
print(data)</code></pre>
<h3>Flask Documentation</h3>
<p>Visit the <a href="https://flask.palletsprojects.com/en/latest/" target="_blank" rel="noopener">Flask documentation here</a></p>
<h3>Flask SQLAlchemy Documentation</h3>
<p>Visit the <a href="https://flask-sqlalchemy.palletsprojects.com/en/2.x/" target="_blank" rel="noopener">Flask SQLAlchemy documentation here</a></p>
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