Amazon DynamoDB Validation

Question

Ich Ausführung folgende DynamoDB Abfrage param aws-Dynamo-Bibliothek in C.

{ "TableName": "table4", "KeyConditionExpression": "#yr = :yyyy and ts between :letter1 and :letter2", "ExpressionAttributeNames": { "#yr": "userid" }, "ExpressionAttributeValues": { ":yyyy": "abc", ":letter1": 1, ":letter2": 2 } } 

mit, aber ich habe Fehler

"__type":"com.amazon.coral.validate#ValidationException","message":"1 validation error detected: Value null at 'hashKeyValue' failed to satisfy constraint: Member must not be null" 

dies ist meine Tabellenstruktur

table4 
{ 
    "Table": { 
     "TableSizeBytes": 66, 
     "KeySchema": [ 
      { 
       "AttributeName": "userid", 
       "KeyType": "HASH" 
      }, 
      { 
       "AttributeName": "ts", 
       "KeyType": "RANGE" 
      } 
     ], 
     "CreationDateTime": 1464617195.039, 
     "ItemCount": 3, 
     "AttributeDefinitions": [ 
      { 
       "AttributeName": "ts", 
       "AttributeType": "N" 
      }, 
      { 
       "AttributeName": "userid", 
       "AttributeType": "S" 
      } 
     ], 
     "ProvisionedThroughput": { 
      "ReadCapacityUnits": 1, 
      "WriteCapacityUnits": 1, 
      "LastDecreaseDateTime": 1464683346.007, 
      "NumberOfDecreasesToday": 1 
     }, 
     "TableStatus": "ACTIVE", 
     "TableName": "table4", 
     "TableArn": "arn:aws:dynamodb:us-east-1:456456456:table/table4" 
    } 
} 

Answer 1

Der Partitionsschlüssel muss in keyconditionexpression enthalten sein. Bitte schließen Sie den Partitionsschlüssel ein und versuchen Sie es. Wenn Sie die Dynamodb abfragen, ist der Partitionsschlüssel zwingend erforderlich. Wenn Sie das Dynamodb scannen, ist der Partitionsschlüssel optional. Dies ist der Hauptunterschied zwischen Abfrage und Scan in dynamodb.

Answer 2

Hier ist die funktionierende Abfrage und Tabellenstruktur.

{ TableName: 'table4', 
KeyConditionExpression: '#userid = :userid AND #ts between :ts1 AND :ts2', 
ExpressionAttributeNames: { '#userid': 'userid', '#ts': 'ts' }, 
ExpressionAttributeValues: { ':userid': 'user1', ':ts1': 1, ':ts2': 2 } } 

Abfrage Ausgabe: -

{"userid":{"S":"user1"},"ts":{"N":"1"}} 

Tabellenstruktur: -

{"Table":{"AttributeDefinitions": 
     [{"AttributeName":"userid","AttributeType":"S"}, 
    {"AttributeName":"ts","AttributeType":"N"}], 
"TableName":"table4","KeySchema": 
[{"AttributeName":"userid","KeyType":"HASH"},{"AttributeName":"ts","KeyType":"RANGE"}], 
"TableStatus":"ACTIVE", 
"CreationDateTime":"2016-05-31T12:46:08.351Z", 
"ProvisionedThroughput":{"LastIncreaseDateTime":"1970-01-01T00:00:00.000Z","LastDecreaseDateTime":"1970-01-01T00:00:00.000Z","NumberOfDecreasesToday":0, 
"ReadCapacityUnits":10,"WriteCapacityUnits":10}, 
"TableSizeBytes":15,"ItemCount":1,"TableArn": 
"arn:aws:dynamodb:ddblocal:000000000000:table/table4"}}