ADD expression for numeric increment in DynamoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to increment the attribute 'count' by 1 using the ADD expression.

DynamoDB

UpdateExpression='ADD count [1]'

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

A'1'

B:one

Cplus 1

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around the number, which makes it a string.

Using a placeholder like ':one' without defining it.

The ADD expression in DynamoDB increments a numeric attribute by the given number. The number must be a numeric literal without quotes.

2fill in blank

medium

Complete the code to increment the attribute 'score' by the value of the variable ':inc' using the ADD expression.

DynamoDB

UpdateExpression='ADD score [1]'

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

A5

B:inc

C'inc'

Dinc

Attempts:

3 left

💡 Hint

Common Mistakes

Using the variable name without colon.

Using quotes around the placeholder.

When using a variable in the ADD expression, you must use a placeholder starting with a colon, like ':inc'.

3fill in blank

hard

Fix the error in the UpdateExpression to correctly increment 'visits' by 2.

DynamoDB

UpdateExpression='ADD visits [1]'

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

A'2'

Btwo

C2

D:two

Attempts:

3 left

💡 Hint

Common Mistakes

Using a string '2' instead of number 2.

Using an undefined placeholder.

The ADD expression requires a numeric literal without quotes to increment by a fixed number.

4fill in blank

hard

Fill both blanks to increment 'likes' by the placeholder value and define the placeholder in ExpressionAttributeValues.

DynamoDB

UpdateExpression='ADD likes [1]'
ExpressionAttributeValues={{'[2]': 3}}

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

A:inc

B:val

C:likes

D:num

Attempts:

3 left

💡 Hint

Common Mistakes

Using different placeholder names in UpdateExpression and ExpressionAttributeValues.

Forgetting the colon ':' in placeholder names.

The placeholder used in UpdateExpression must match the key in ExpressionAttributeValues. Here, ':inc' is used in both places.

5fill in blank

hard

Fill all three blanks to increment 'points' by a variable, define the placeholder, and use the correct attribute name.

DynamoDB

UpdateExpression='ADD [1] [2]'
ExpressionAttributeValues={{'[3]': 10}}

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

Apoints

B:pts

C:points

Dscore

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different attribute name than 'points'.

Mismatch between placeholder in expression and attribute values.

The attribute name is 'points'. The placeholder ':pts' is used in UpdateExpression and defined in ExpressionAttributeValues.