A Step Functions Task state calling DynamoDB GetItem returns null for an existing key. What is a likely cause?

medium📝 Debug Q7 of 15

DynamoDB - with Serverless

AThe Task state is missing the ResultPath field

BThe DynamoDB table is empty

CThe Key attribute names or types do not exactly match the table's primary key

DThe Step Functions state machine is missing a StartAt field

Step-by-Step Solution

Solution:

Step 1: Understand GetItem null result
GetItem returns null if the key does not match any item exactly.
Step 2: Analyze other options
Table empty means no items; missing ResultPath or StartAt cause different errors, not null result.
Final Answer:
The Key attribute names or types do not exactly match the table's primary key -> Option C
Quick Check:
Null GetItem result = key mismatch [OK]

Quick Trick: Key names and types must exactly match DynamoDB primary key [OK]

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