Dynamodb: Querying tables with secondary index
amazon-dynamodb, amazon-web-services, ruby
Solution
You are not querying the secondary index, you are querying the primary index(hash and range key). To use a secondary index with DynamoDB you must use V2 of the API and specify the index in the query operation
client = AWS::DynamoDB::Client.new(api_version: '2012-08-10')
client.query( { :table_name: 'table', :index_name: "timestamp-index", :select: 'ALL_PROJECTED_ATTRIBUTES', :key_conditions: {
'hk' => {
:comparison_operator: 'EQ',
:attribute_value_list: [
{'s' => 'aaaa'}
]
},
'timestamp' => {
:comparison_operator: 'GE',
:attribute_value_list: [
{'s' => Time.now.utc.iso8601}
]
} } })
Problem
I am using the gem aws-sdk-ruby to query a table which looks something like this: ``` hk (Hashkey) | guid(Rangekey) | Timestamp (Secondary Range index) | other attributes aaaa | 50 | 2013-02-04T12:33:00Z | aaaa | 244 | 2013-04-22T04:54:00Z | aaaa | 342 | 2013-05-18T06:52:00Z | bbbb | 243 | 2013-06-21T13:17:00Z | ``` What I am trying to do is get all 'aaaa' rows that were created after a certain date. Ex: ``` AWS.config(access_key_id: 'xxx', secret_access_key: 'xxx', :dynamo_db => { :api_version => '2012-08-10' }) client = AWS::DynamoDB::Client.new client.query( { table_name: 'table', select: 'ALL_ATTRIBUTES', key_conditions: { 'hk' => { comparison_operator: 'EQ', attribute_value_list: [ {'s' => 'aaaa'} ] }, 'timestamp' => { comparison_operator: 'GE', attribute_value_list: [ {'s' => Time.now.utc.iso8601} ] } } }) ``` When i run the code above i get this: ``` Query condition missed key schema element guid (AWS::DynamoDB::Errors::ValidationException) ``` Running the query with hashKey and RangeKey works but when i replace the rangeKey with a secondary range index it fails telling me that the rangeKey is required. If i then add the range key (Which makes no sense) i get the following error instead: ``` Conditions can be of length 1 or 2 only (AWS::DynamoDB::Errors::ValidationException) ``` Anyone know what might be happening?