AWS DynamoDb querying a table - node.js

Question

I am trying to use Dynamodb on a new project and i have to say i am very confused.
So i have setup a new table with a hash key called ID which i am setting as a timestamp as it needs to be unique.
I am then inserting my data as follow with Lambda
var tableName = "TrackerTable";
var datetime = new Date().getTime().toString();
var putData = {
"TableName": tableName,
"Item": {
"ID" : {
"N": datetime
},
"TrackIt": {
"S": event.trackit
},
"Latitude": {
"N": event.lat
},
"Longitude": {
"N": event.lon
},
"Time": {
"N": datetime
}
}
}
dynamoDB.putItem(putData, function(err, data) {
if (err) {
context.fail('ERROR: Dynamo failed: ' + err);
} else {
console.log('Dynamo Success: ' + JSON.stringify(data, null, ' '));
context.succeed('SUCCESS');
}
});
So my table starts to look like this which is fine.
So i am trying to use Lambda to return my results based on the trackit column?
I have the following code which doesnt work.
var tableName = "TrackerTable";
var datetime = new Date().getTime().toString();
var queryData = {
"TableName": tableName,
"ConsistentRead": true,
"KeyConditionExpression": "trackit = :val",
"ExpressionAttributeValues": {":val": {"S": "05LUGFr7494"}}
};
dynamoDB.query(queryData, function(err, data) {
if (err) {
context.fail('ERROR: Dynamo failed: ' + err);
}else{
console.log('Dynamo Success: ' + JSON.stringify(data, null, ' '));
context.done(null, data.Items);
}
});
I get this error.
{
"errorMessage": "ERROR: Dynamo failed: ValidationException: Query condition missed key schema element: ID"
}
How can i query all the trackit values i cant add the ID value as it will only return one value?
Very confused.

Answer 1

The way you have your table setup I think you'll need to do a scan here instead of a query[1]. If this is an operation that your will be doing frequently and want to have the ability to do a query, you would need to add the trackit property as one of your secondary indexes.
[1] http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/QueryAndScan.html