GetItem from Secondary Index with DynamoDB - amazon-dynamodb

Question

I'm just getting started using DynamoDB and have setup an 'accounts' table.
I've set-up a secondary index so I can query an api user and user key.
Neither of these values are the primary key, as they are both volatile and can be changed.
The Table is built with
TableName: "Accounts",
KeySchema: [
{ AttributeName: "id", KeyType: "HASH" },
{ AttributeName: "email", KeyType: "RANGE" }
],
AttributeDefinitions: [
{ AttributeName: "id", AttributeType: "S" },
{ AttributeName: "email", AttributeType: "S" }
]
And the Index is
TableName: 'Accounts',
AttributeDefinitions: [
{AttributeName: 'name', AttributeType: 'S'},
{AttributeName: 'apiKey', AttributeType: 'S'}
],
GlobalSecondaryIndexUpdates: [
{
Create: {
IndexName: "ApiAccounts",
ProvisionedThroughput: {
ReadCapacityUnits: 1, WriteCapacityUnits: 1
},
KeySchema: [
{AttributeName: 'name', KeyType: "HASH"},
{AttributeName: 'apiKey', KeyType: "STRING"}
],
Projection: {
ProjectionType: "KEYS_ONLY"
},
I'm now trying to get a uses account by querying the ApiAccounts index.
I'm trying
dynamoClient.get({
TableName: 'Accounts',
IndexName: 'ApiAccounts',
Key: {
name: nameKeyArray[0],
apiKey: nameKeyArray[1]
}, callback)
But I am getting an error One of the required keys was not given a value, which leads me to believe I can't do a 'get' on a Index? Or I'm not referring the index properly. Can somebody clarify for me?
Name and API Key are unique, so I think I want to avoid a query or scan if possible

Answer 1

I guess its not so clear from the official docs. You may perform Scan or Query operation on GSI index, but not the GetItem operation.
For every record / item in a Table, they must have unique HASH and RANGE keys.
i.e.
// assume dummy api putItem(id, email, name, apiKey)
account.putItem("1", "abc#email.com", "john", "key1") // OK
account.putItem("1", "abc#email.com", "john", "key1") // NOT OK, id and email are table HASH and RANGE keys, must be unique
But for Index'es, Hash and Range keys are not unique, they may contain duplicated records / items.
i.e.
// assume dummy api putItem(id, email, name, apiKey)
account.putItem("1", "abc#email.com", "john", "key1") // OK
account.putItem("1", "bcd#email.com", "john", "key1") // OK
i.e.
// assume dummy api putItem(id, email, name, apiKey)
account.putItem("1", "abc#email.com", "john", "key1") // OK
account.putItem("2", "abc#email.com", "john", "key1") // OK
Java
http://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/dynamodbv2/document/Index.html
Index implements QueryApi and ScanApi but not GetItemApi.
JavaScript
http://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/DynamoDB.html#getItem-property
GetItem does not accept IndexName as a parameter.
http://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/DynamoDB.html#query-property
Query accepts IndexName as a parameter.
http://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/DynamoDB.html#scan-property
Scan accepts IndexName as a parameter.