[英]AWS DynamoDB Batch Get Request - iOS
I can perform a simple Get
request on a singular table within AWS dynamoDB however when I expand it to a Batch Request across multiple tables I continue to get a error 我可以在AWS dynamoDB中的单个表上执行简单的
Get
请求,但是当我将它扩展到跨多个表的批处理请求时,我仍然会收到错误
validation error detected: Value null at 'requestItems.rip.member.keys' failed to satisfy constraint
I understand this as the values not being passed correctly but I can't see what the issue is with my code 我理解这是因为没有正确传递值,但我无法看到我的代码存在什么问题
//Create Request Values
AWSDynamoDBGetItemInput *getItem = [AWSDynamoDBGetItemInput new];
AWSDynamoDBAttributeValue *hashValue = [AWSDynamoDBAttributeValue new];
hashValue.S = @"User Test";
getItem.key = @{@"ripId": hashValue};
//Create Request Values 2
AWSDynamoDBGetItemInput *getItem2 = [AWSDynamoDBGetItemInput new];
AWSDynamoDBAttributeValue *hashValue2 = [AWSDynamoDBAttributeValue new];
hashValue2.S = @"User Test";
getItem2.key = @{@"chat": hashValue2};
//Combine to Batch Request
AWSDynamoDBBatchGetItemInput * batchFetch = [AWSDynamoDBBatchGetItemInput new];
batchFetch.requestItems = @{ @"rip": getItem,
@"chat": getItem,};
[[dynamoDB batchGetItem:batchFetch] continueWithBlock:^id(BFTask *task) {
if (!task.error) {
NSLog(@"BOY SUCCES");
} else {
NSLog(@" NO BOY SUCCESS %@",task.error);
}
return nil;
}];
Searched the internet high and low but cannot see a working example of a batch request using iOS Objective C (or swift for that matter). 搜索了互联网的高低,但无法看到使用iOS Objective C(或swift)的批量请求的工作示例。
I have tested both variables on a single Get
request and they both work. 我已在单个
Get
请求中测试了这两个变量,但它们都有效。
You forgot to wrap around AWSDynamoDBAttributeValue
in AWSDynamoDBKeysAndAttributes
. 您忘了在
AWSDynamoDBAttributeValue
中包装AWSDynamoDBKeysAndAttributes
。 Here is a simple example from AWSDynamoDBTests.m : 以下是AWSDynamoDBTests.m中的一个简单示例:
AWSDynamoDBKeysAndAttributes *keysAndAttributes = [AWSDynamoDBKeysAndAttributes new];
keysAndAttributes.keys = @[@{@"hashKey" : attributeValue1},
@{@"hashKey" : attributeValue2}];
keysAndAttributes.consistentRead = @YES;
AWSDynamoDBBatchGetItemInput *batchGetItemInput = [AWSDynamoDBBatchGetItemInput new];
batchGetItemInput.requestItems = @{table1Name: keysAndAttributes};
Since the batch get doesn't map to a class I solved it by doing this instead. 由于批处理get没有映射到类,我通过这样做来解决它。
I solved it by doing this, 我解决了这个问题,
let dynamoDBObjectMapper = AWSDynamoDBObjectMapper.defaultDynamoDBObjectMapper()
let task1 = dynamoDBObjectMapper.load(User.self, hashKey: "rtP1oQ5DJG", rangeKey: nil)
let task2 = dynamoDBObjectMapper.load(User.self, hashKey: "dbqb1zyUq1", rangeKey: nil)
AWSTask.init(forCompletionOfAllTasksWithResults: [task1, task2]).continueWithBlock { (task) -> AnyObject? in
if let users = task.result as? [User] {
print(users.count)
print(users[0].firstName)
print(users[1].firstName)
}
else if let error = task.error {
print(error.localizedDescription)
}
return nil
}
let DynamoDB = AWSDynamoDB.default() // define your primary hash keys let hashAttribute1 = AWSDynamoDBAttributeValue() hashAttribute1?.s = "NDlFRTdDODEtQzNCOC00QUI5LUFFMzUtRkIyNTJFNERFOTBF" let hashAttribute2 = AWSDynamoDBAttributeValue() hashAttribute2?.s = "MjVCNzU3MUQtMEM0NC00NEJELTk5M0YtRTM0QjVDQ0Q1NjlF" let keys: Array = [["userID": hashAttribute1], ["userID": hashAttribute2]] let keysAndAttributesMap = AWSDynamoDBKeysAndAttributes() keysAndAttributesMap?.keys = keys as? [[String : AWSDynamoDBAttributeValue]] keysAndAttributesMap?.consistentRead = true let tableMap = ["Your-Table-Name" : keysAndAttributesMap] let request = AWSDynamoDBBatchGetItemInput() request?.requestItems = tableMap as? [String : AWSDynamoDBKeysAndAttributes] request?.returnConsumedCapacity = AWSDynamoDBReturnConsumedCapacity.total DynamoDB.batchGetItem(request!) { (output, error) in if output != nil { print("Batch Query output?.responses?.count:", output!.responses!) } if error != nil { print("Batch Query error:", error!) } }
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