Why DynamoDB for NoSQL in AWS - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a DynamoDB table with a primary key.

AWS

aws dynamodb create-table --table-name Users --attribute-definitions AttributeName=UserId,AttributeType=S --key-schema AttributeName=UserId,KeyType=[1] --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5

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AINDEX

BHASH

CPRIMARY

DRANGE

Attempts:

3 left

💡 Hint

Common Mistakes

Using RANGE instead of HASH for the primary key.

Confusing key types with index types.

The primary key in DynamoDB is defined as a HASH key. This uniquely identifies each item in the table.

2fill in blank

medium

Complete the code to add a Global Secondary Index (GSI) to the DynamoDB table.

AWS

aws dynamodb update-table --table-name Users --attribute-definitions AttributeName=Email,AttributeType=S --global-secondary-index-updates '[{"Create":{"IndexName":"EmailIndex","KeySchema":[{"AttributeName":"Email","KeyType":"[1]"}],"Projection":{"ProjectionType":"ALL"},"ProvisionedThroughput":{"ReadCapacityUnits":5,"WriteCapacityUnits":5}}}]'

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AHASH

BRANGE

CPRIMARY

DSORT

Attempts:

3 left

💡 Hint

Common Mistakes

Using RANGE instead of HASH for the GSI partition key.

Confusing primary key with index key.

The partition key for a Global Secondary Index must be a HASH key.

3fill in blank

hard

Fix the error in the DynamoDB query to get an item by its primary key.

AWS

aws dynamodb get-item --table-name Users --key '{"UserId": {"[1]": "12345"}}'

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ASS

BN

CBOOL

DS

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'N' which is for numbers.

Using 'BOOL' which is for boolean values.

The attribute type for a string in DynamoDB JSON format is 'S'.

4fill in blank

hard

Fill both blanks to write a DynamoDB update expression that sets a new attribute and increments a counter.

AWS

aws dynamodb update-item --table-name Users --key '{"UserId": {"S": "12345"}}' --update-expression "SET [1] = :val, [2] = [2] + :inc" --expression-attribute-values '{":val": {"S": "active"}, ":inc": {"N": "1"}}'

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AStatus

BCounter

CAge

DScore

Attempts:

3 left

💡 Hint

Common Mistakes

Using the same attribute for both set and increment.

Using attributes that do not exist in the table.

The update expression sets the 'Status' attribute and increments the 'Counter' attribute.

5fill in blank

hard

Fill all three blanks to write a DynamoDB query that filters items with Age greater than 25 and projects only Name and Age.

AWS

aws dynamodb scan --table-name Users --filter-expression "[1] > :age" --expression-attribute-names '{"#N": "[2]", "#A": "[3]"}' --expression-attribute-values '{":age": {"N": "25"}}' --projection-expression "#N, #A"

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AAge

BName

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing attribute names in filter and projection expressions.

Not using expression attribute names for reserved words.

The filter expression uses 'Age' to compare, and the projection expression uses 'Name' and 'Age' attributes.