Cant update Dynamo Db table , getting ValidationException
<p>I need to update my dynamo db table by using only partition key. But i got validation exeption. 
I have created a table with 3 fields. </p>

<ol>
<li>id (Partition Key)</li>
<li>name (Sort Key)</li>
<li>age</li>
</ol>

<p>Then i have triyed to update age field using only id.(tryied to modify age 30 to 40) this is my code</p>

<pre><code>var AWS = require("aws-sdk");

AWS.config.update({
    region: "us-east-1",

});

var params = {
    TableName: 'test',
    Key: { id: '100' },
    UpdateExpression: 'set #age = :age ',
    ConditionExpression: '#age = :testAge',
    ExpressionAttributeNames: { '#age': 'age' },
    ExpressionAttributeValues: { ':age': '40', ':testAge': '30' }
};

var docClient = new AWS.DynamoDB.DocumentClient();
docClient.update(params, function (err, data) {
    if (err) {
        console.log(err);
    }
    else {
        console.log(data);
    }
});
</code></pre>

<p>But i got error like this. </p>

<pre><code>{ [ValidationException: The provided key element does not match the schema]
  message: 'The provided key element does not match the schema',
  code: 'ValidationException',
  time: Thu Nov 17 2016 22:38:01 GMT+0530 (IST),
  requestId: '34PNMFM6CEACQIRHTSV77OI0JRVV4KQNSO5AEMVJF66Q9ASUAAJG',
  statusCode: 400,
  retryable: false,
  retryDelay: 0 }
</code></pre>

<p>After getting error, i modified my params variable like this</p>

<pre><code> var params = {
        TableName: 'test',
        Key: { id: '100',name: 'manaf' },
        UpdateExpression: 'set #age = :age ',
        ConditionExpression: '#age = :testAge',
        ExpressionAttributeNames: { '#age': 'age' },
        ExpressionAttributeValues: { ':age': '40', ':testAge': '30' }
    };
</code></pre>

<p>Using this, updation is successfully completed. How to update table using without sort key?</p>