title: One of the required keys was not given a value - AWS
body: <p>I am new to DynamoDB and I was trying to design a table and do some proof of concept. Below is the table I created with Local Secondary Index</p>
  
  <pre><code>var params = {
          TableName : "sample",
          KeySchema: [
              { AttributeName: "user_id", KeyType: "HASH"},
              { AttributeName: "created_date", KeyType: "RANGE"}
          ],
          AttributeDefinitions: [
              { AttributeName: "user_id", AttributeType: "S" },
              { AttributeName: "created_date", AttributeType: "S" },
              { AttributeName: "video_id", AttributeType: "S" }
  
          ],
          ProvisionedThroughput: {
              ReadCapacityUnits: 5,
              WriteCapacityUnits: 5
          },
          LocalSecondaryIndexes: [{
                  IndexName: "user_id-video_id-Index",
                  KeySchema: [
                      {
                          AttributeName: "user_id",
                          KeyType: "HASH"
                      },
                      {
                          AttributeName: "video_id",
                          KeyType: "RANGE"
                      }
                  ],
                  Projection: {
                      ProjectionType: "ALL"
                  }
              }]
  </code></pre>
  
  <p>And after this I have inserted two items as below</p>
  
  <p>Item 1:</p>
  
  <pre><code>{
      "company": "comapnyname",
      "created_date": "02-28-2019",
      "email": "randomguy@abc.com",
      "first_name": "John",
      "last_name": "Doe",
      "profile_pic": "https://s3location",
      "user_id": "vshdhfb"
    }
  </code></pre>
  
  <p>Item 2:</p>
  
  <pre><code>{
                  "author": "Phil DiMaggio",
                  "created_date": "02-29-2018",
                  "description": "This video further introduces the Business Sales compensation plans.",
                  "likes": "12",
                  "title": "Understanding Business Sales Compensation Plans",
                  "user_id": "vshdhfb",
                  "video_id": "vdhk23so9",
                  "video_loc": "https://s3.amazonaws.com/videos/video.mp4",
                  "views": "45"
                }
  </code></pre>
  
  <p>And then I try to update/delete the second item with below code and it gives me an error as "message": "One of the required keys was not given a value" </p>
  
  <pre><code>var params = {
          TableName: "sample",
  
          Key:{
              "video_id": "vdhk23so9",
              "user_id":"vshdhfb"
          },
          UpdateExpression: "set likes = likes + :val",
          ExpressionAttributeValues:{
          ":val":1
          },
          ReturnValues:"UPDATED_NEW"
      };
  
      docClient.update(params, function(err, data) {
          if (err) {
              document.getElementById('textarea').innerHTML = "Unable to update like: " + "\n" + JSON.stringify(err, undefined, 2);
          } else {
              document.getElementById('textarea').innerHTML = "Like video succeeded: " + "\n" + JSON.stringify(data, undefined, 2);
          }
      });
  } 
  </code></pre>
  
  <p>Do I need to add another key ? What am I missing ? </p>