const primaryKey = "4234241";
const tableSpec = {
    TableName: 'tableName',
    Item: params,
    ConditionExpression: '#primaryId <> :primaryId',
    ExpressionAttributeNames: {'#primaryId': 'primaryId'},
    ExpressionAttributeValues: {
        ':primaryValue': primaryValue
    }
  };
  var docClient = new AWS.DynamoDB.DocumentClient();
  docClient.put(tableSpec, function (err, data) {
    if (err) {
      console.log(err);
    }
  });