Composite primary key in DynamoDB - Mini Project: Build & Apply

Create a DynamoDB Table with Composite Primary Key

📖 Scenario: You are building a simple database for an online bookstore. Each book can have multiple editions, and you want to store information about each edition separately. To uniquely identify each edition, you will use a composite primary key in DynamoDB.

🎯 Goal: Create a DynamoDB table named Books with a composite primary key consisting of ISBN as the partition key and Edition as the sort key.

📋 What You'll Learn

Create a DynamoDB table named Books

Use ISBN as the partition key (string type)

Use Edition as the sort key (number type)

Add an attribute Title (string type) to store the book title

💡 Why This Matters

🌍 Real World

Composite primary keys help uniquely identify items in databases where a single attribute is not enough, such as different editions of the same book.

💼 Career

Understanding composite keys is essential for designing efficient NoSQL databases like DynamoDB, commonly used in cloud applications.

1

Define the Table Name and Partition Key

Create a variable called table_name and set it to the string 'Books'. Then create a dictionary called key_schema with one entry: a dictionary with AttributeName set to 'ISBN' and KeyType set to 'HASH'.

DynamoDB

# Create table_name and key_schema variables
# Your code here

Need a hint?

The partition key is called the HASH key in DynamoDB. Use a list with one dictionary for key_schema.

2

Add the Sort Key to the Key Schema

Add a second dictionary to the key_schema list with AttributeName set to 'Edition' and KeyType set to 'RANGE' to define the sort key.

DynamoDB

table_name = 'Books'
key_schema = [{
    'AttributeName': 'ISBN',
    'KeyType': 'HASH'
}]
# Add the sort key dictionary to key_schema
# Your code here

Need a hint?

The sort key is called the RANGE key in DynamoDB. Add it as the second item in the key_schema list.

3

Define Attribute Definitions

Create a list called attribute_definitions with two dictionaries: one for ISBN with AttributeType set to 'S' (string), and one for Edition with AttributeType set to 'N' (number).

DynamoDB

table_name = 'Books'
key_schema = [{
    'AttributeName': 'ISBN',
    'KeyType': 'HASH'
}, {
    'AttributeName': 'Edition',
    'KeyType': 'RANGE'
}]
# Define attribute_definitions list
# Your code here

Need a hint?

Attribute types use 'S' for string and 'N' for number in DynamoDB.

4

Add Table Creation Parameters

Create a dictionary called table_params with keys: TableName set to table_name, KeySchema set to key_schema, AttributeDefinitions set to attribute_definitions, and BillingMode set to 'PAY_PER_REQUEST'.

DynamoDB

table_name = 'Books'
key_schema = [{
    'AttributeName': 'ISBN',
    'KeyType': 'HASH'
}, {
    'AttributeName': 'Edition',
    'KeyType': 'RANGE'
}]

attribute_definitions = [{
    'AttributeName': 'ISBN',
    'AttributeType': 'S'
}, {
    'AttributeName': 'Edition',
    'AttributeType': 'N'
}]

# Create table_params dictionary
# Your code here

Need a hint?

Use PAY_PER_REQUEST billing mode for simplicity.