Computer Science
Grade 10
20 min
Connecting Flask to a Database: Basic CRUD Operations
Learn how to connect Flask to a database and perform basic CRUD (Create, Read, Update, Delete) operations.
What you'll learn
- Identify the four basic CRUD operations (Create, Read, Update, Delete) and their corresponding SQL commands (INSERT, SELECT, UPDATE, DELETE) with 100% accuracy.
- Explain the process of connecting a Flask application to a SQLite database using the `sqlite3` module and describe the purpose of each line of code in the connection script with 80% accuracy.
- Apply the learned CRUD operations to build a Flask application that can add, view, modify, and delete data entries in a database table based on a provided schema, with at least 3 out of 4 CRUD operations functioning correctly.
- Debug and troubleshoot common errors encountered when connecting Flask to a database, such as incorrect database paths or SQL syntax errors, and successfully resolve at least 2 out of 3 given error scenarios.
Tutorial Preview
1
Introduction & Learning Objectives
Learning Objectives
Define the four CRUD operations (Create, Read, Update, Delete) and their purpose in web applications.
Set up a simple SQLite database and connect it to a Flask application using Flask-SQLAlchemy.
Implement the 'Create' operation by processing an HTML form to add new data to the database.
Implement the 'Read' operation by querying the database and displaying all records on a web page.
Implement the 'Update' operation to edit an existing database record through a web interface.
Implement the 'Delete' operation to remove a specific record from the database based on user input.
Ever wonder how Instagram saves your photos or how your favorite game saves your high score? 🏆 It's all about talking to a database!
In t...
2
Key Concepts & Vocabulary
TermDefinitionExample
CRUDAn acronym for the four basic functions of persistent storage: Create, Read, Update, and Delete. These are the fundamental operations for interacting with any database.In a contacts app: Creating a new contact, Reading the list of all contacts, Updating a phone number, and Deleting a contact.
DatabaseAn organized collection of structured information, or data, typically stored electronically in a computer system, allowing for efficient retrieval and management.A spreadsheet file containing a table of student names, IDs, and grades.
Flask-SQLAlchemyA Flask extension that adds support for SQLAlchemy, an Object-Relational Mapper (ORM). It lets us interact with our database using Python objects and methods instead of writing raw SQL commands.Instead of writing `INSERT...
3
Core Syntax & Patterns
Defining a Database Model
class ModelName(db.Model):
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(100), nullable=False)
Use this class structure to define a table in your database. Each class variable using `db.Column` becomes a column in the table, with a specified data type (like Integer or String).
Creating and Saving a New Record (Create)
new_record = ModelName(name='value')
db.session.add(new_record)
db.session.commit()
To add a new row, first create an instance of your model class with the data. Then, use `db.session.add()` to stage it for saving, and `db.session.commit()` to write it permanently to the database.
Querying for Records (Read)
all_records = ModelName.query.all()
single_record = ModelName.query.get(primary_key...
4 more steps in this tutorial
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Sign Up Free to ContinueSample Practice Questions
Easy
What does the 'C' in the acronym CRUD stand for in the context of database operations?
A.Commit
B.Create
C.Column
D.Class
Easy
In Flask-SQLAlchemy, what base class must a database model inherit from to define a table structure?
A.db.Table
B.Flask.Model
C.db.Model
D.SQLAlchemy.Table
Easy
Which Flask-SQLAlchemy command is used to make changes to the database permanent, similar to saving a file?
A.db.session.add()
B.db.session.save()
C.db.session.execute()
D.db.session.commit()
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Connecting Flask to a Database: Basic CRUD Operations is a Grade 10 Computer Science lesson on ExcelOS.
What will I learn in Connecting Flask to a Database: Basic CRUD Operations?
You'll be able to: Identify the four basic CRUD operations (Create, Read, Update, Delete) and their corresponding SQL commands (INSERT, SELECT, UPDATE, DELETE) with 100% accuracy; Explain the process of connecting a Flask application to a SQLite….
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How many practice questions are included with Connecting Flask to a Database: Basic CRUD Operations?
This lesson includes 25 practice questions across multiple difficulty levels, each with instant feedback and explanations.