rest api gateway in front of dynamodb gives 404 on GET calls

Question

Hi,
I am following [this guide](https://medium.com/brlink/rest-api-just-with-apigateway-and-dynamodb-8a9b0cd76b7a) to create a test REST api gw in front of a dynamo db table.

While the POST call tests work,  when I try the GET  to retrieve a username I always get a 404

```

Fri Feb 11 07:17:40 UTC 2022 : Endpoint request URI: https://dynamodb.us-east-1.amazonaws.com/?Action=Query
Fri Feb 11 07:17:40 UTC 2022 : Endpoint request headers: {Authorization=****************************************************************************************************************************************************************************************************************************************************************************************82e823, X-Amz-Date=20220211T071740Z, x-amzn-apigateway-api-id=2xxp28f39k, Accept=application/json, User-Agent=AmazonAPIGateway_2xxp28f39k, X-Amz-Security-Token=xxxxx
Fri Feb 11 07:17:40 UTC 2022 : Endpoint request body after transformations: {
    "TableName": "users",
    "IndexName": "username-index",
    "KeyConditionExpression": "username = :val",
    "ExpressionAttributeValues": {
        ":val": {
            "S": "ABE"
        }
    }
}
Fri Feb 11 07:17:40 UTC 2022 : Sending request to https://dynamodb.us-east-1.amazonaws.com/?Action=Query
Fri Feb 11 07:17:40 UTC 2022 : Received response. Status: 404, Integration latency: 2 ms
```

this is my GET integration request application/json mapping template

```

{
    "TableName": "users",
    "IndexName": "username-index",
    "KeyConditionExpression": "username = :val",
    "ExpressionAttributeValues": {
        ":val": {
            "S": "$input.params('username')"
        }
    }
}
```

If I test the query on dynamodb it works:

```
aws dynamodb query \
    --table-name $tablename \
    --index-name $indexname \
    --key-condition-expression "username = :v1" \
    --expression-attribute-values file://expression-attributes.json \
    --select ALL_PROJECTED_ATTRIBUTES \
    --return-consumed-capacity INDEXES
```

where file://expression-attributes.json

```
{
    ":v1": {"S": "ABE"}
}

gives

```
{
    "Items": [
        {
            "realname": {
                "S": "xxxxx"
            },
            "username": {
                "S": "ABE"
            },
            "uid": {
                "S": "fc1d4fa5-6157-47c7-85a7-3953e477b396"
            }
        }
		
```
any idea what I am missing?

Accepted Answer

For the GET method Integration Request, ensure you choose **POST** for the **HTTP method** since all DynamoDB Queries are POST.

Answer

From a really quick glance it seems you do not pass the username in to the query string:
```https://dynamodb.us-east-1.amazonaws.com/?Action=Query```

Have you enabled CloudWatch logging on your API GW Endpoint? Should see better information there.

https://docs.aws.amazon.com/apigateway/latest/developerguide/set-up-logging.html

Answer

Bingo! I needed POST in DynamoDB integration
"spasiba"

rest api gateway in front of dynamodb gives 404 on GET calls

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