Key condition expressions in DynamoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to query items with a specific partition key.

DynamoDB

response = table.query(KeyConditionExpression=Key('UserId').[1](':user_id'))

Drag options to blanks, or click blank then click option'

A==

Bequals

C=

Deq

Attempts:

3 left

💡 Hint

Common Mistakes

Using Python equality operators like '==' or '=' instead of the DynamoDB method 'eq'.

Using 'equals' which is not a valid method in DynamoDB expressions.

In DynamoDB, the KeyConditionExpression uses the eq method to specify equality for the partition key.

2fill in blank

medium

Complete the code to query items with a partition key and sort key greater than a value.

DynamoDB

response = table.query(KeyConditionExpression=Key('UserId').eq(':user_id') & Key('Timestamp').[1](':time_val'))

Drag options to blanks, or click blank then click option'

Agt

Blt

Ceq

Dlte

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'lt' which means less than, the opposite of what is needed.

Using 'eq' which checks for equality, not greater than.

The gt method means 'greater than' and is used to filter sort keys greater than a given value.

3fill in blank

hard

Fix the error in the key condition expression to query items with a partition key and sort key less than or equal to a value.

DynamoDB

response = table.query(KeyConditionExpression=Key('UserId').eq(':user_id') & Key('Timestamp').[1](':time_val'))

Drag options to blanks, or click blank then click option'

Agt

Bgte

Clte

Dlt

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'lt' which means strictly less than, not including equal.

Using 'gte' or 'gt' which filter for greater values.

The lte method means 'less than or equal to', which fixes the error for the intended query.

4fill in blank

hard

Fill both blanks to query items with a partition key equal to a value and a sort key between two values.

DynamoDB

response = table.query(KeyConditionExpression=Key('UserId').[1](':user_id') & Key('Timestamp').[2](':start_time', ':end_time'))

Drag options to blanks, or click blank then click option'

Aeq

Bgt

Cbetween

Dlt

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'gt' or 'lt' for the partition key which requires equality.

Using 'eq' for the sort key when a range is needed.

The partition key uses eq for equality, and the sort key uses between to specify a range.

5fill in blank

hard

Fill all three blanks to query items with a partition key equal to a value, a sort key greater than a value, and less than or equal to another value.

DynamoDB

response = table.query(KeyConditionExpression=Key('UserId').[1](':user_id') & Key('Timestamp').[2](':start_time') & Key('Timestamp').[3](':end_time'))

Drag options to blanks, or click blank then click option'

Aeq

Bgt

Clte

Dlt

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'lt' instead of 'lte' for the upper bound.

Using 'eq' for sort key conditions instead of range comparisons.

The partition key uses eq for equality, the sort key uses gt for greater than the start time, and lte for less than or equal to the end time.