Unable to fetch an item in AWS DynamoDB

Environment:

NodeJS used with "aws-sdk": "^2.1692.0" to test DynamoDB operations

Goal:

To fetch an item in an exsiting table called CUSTOMER_LIST which contains a list of items.

When I used putItem method to store data, it was a success with the given schema,

 var params = {
  TableName: "CUSTOMER_LIST",
  Item: {
    CUSTOMER_ID: { N: "001" },
    CUSTOMER_NAME: { S: "Richard Roe" },
  },
};

And when I want to fetch an item(getItem method), the given schema is,

   var params = {
      TableName: 'CUSTOMER_LIST',
      Key: {
        "CUSTOMER_ID": { N: "001" },
      },
      ProjectionExpression: 'CUSTOMER_NAME',
    };

but I end up having an error in the console given below

Error ValidationException: The provided key element does not match the schema

The same error is also thrown out for deletion of an item.

Here's a link from the AWS documentation from where the example has been taken.

You have set CUSTOMER_NAME as the sort key, and in DynamoDB to do a GetItem you must provide the full primary key (partition and sort).

If you want to do a fetch with just the partition key, you must use Query operation:

var params = {
  TableName: 'CUSTOMER_LIST',
  KeyConditionExpression: 'CUSTOMER_ID = :id',
  ExpressionAttributeValues: {
    ':id': { N: '001' }
  },
  ProjectionExpression: 'CUSTOMER_NAME'
};

Then query instead of getItem:

dynamodb.query(params, function(err, data) {
  if (err) {
    console.error("Query failed:", JSON.stringify(err, null, 2));
  } else {
    console.log("Query succeeded:", JSON.stringify(data.Items, null, 2));
  }
});