dynamodb scanex pression用Objective-C的扫描过滤器 [英] dynamodb scanexpression with scan filter in objective-c

问题描述

  AWSDynamoDBObjectMapper * dynamoDBObjectMapper = [AWSDynamoDBObjectMapper defaultDynamoDBObjectMapper]
    AWSDynamoDBScanEx pression * scanEx pression = [AWSDynamoDBScanEx pression新]。
    scanEx pression.exclusiveStartKey =零;
    scanEx pression.limit = @ 20;
    [[[dynamoDBObjectMapper扫描：[DDBTableRow类]
                      EX pression：scanEx pression]
      continueWithExecutor：[BFExecutor mainThreadExecutor] withSuccessBlock：^ ID（BFTask *任务）{................
 

我能够扫描并从我的DynamoDB返回从特定的表记录的第20为显示在一张code以上。

现在的问题是我想添加一个 scanEx pression.scanFilter = 属性，但我还没有找到如何建立，任何好的方向发展。我使用 AWSiOSSDKv2 AWS SDK的iOS上的 X code6

这里是我到目前为止所。它尚未完成：

  AWSDynamoDBCondition *条件= [AWSDynamoDBCondition新]
    AWSDynamoDBAttributeValue *属性= [AWSDynamoDBAttributeValue新]
    attribute.N = @400;
    condition.comparisonOperator = AWSDynamoDBComparisonOperatorEQ;

    的NSDictionary * scanFilter = @ {@纬度：
                                     @ {@AttributeValueList：属性，
                                       @ComparisonOperator：@ 1}
                                 };
    scanEx pression.scanFilter = scanFilter;
 

解决方案

您可以使用它，如下所示：

  AWSDynamoDBCondition *条件= [AWSDynamoDBCondition新]
AWSDynamoDBAttributeValue *属性= [AWSDynamoDBAttributeValue新]
attribute.N = @400;
condition.attributeValueList = @ [属性]。
condition.comparisonOperator = AWSDynamoDBComparisonOperatorEQ;
scanEx pression.scanFilter = @ {@纬度：条件};
 

    AWSDynamoDBObjectMapper *dynamoDBObjectMapper = [AWSDynamoDBObjectMapper defaultDynamoDBObjectMapper];
    AWSDynamoDBScanExpression *scanExpression = [AWSDynamoDBScanExpression new];
    scanExpression.exclusiveStartKey = nil;
    scanExpression.limit = @20;
    [[[dynamoDBObjectMapper scan:[DDBTableRow class]
                      expression:scanExpression]
      continueWithExecutor:[BFExecutor mainThreadExecutor] withSuccessBlock:^id(BFTask *task) { ................

I am able to scan through and return the first 20 recorded from a specific table from my DynamoDB as shows on a piece of code above.

The question now is I want to add a scanExpression.scanFilter = property but I haven't find any good direction on how to build that. I am using AWSiOSSDKv2 aws sdk for iOS on xcode6

here is what I have so far. It is not complete yet:

    AWSDynamoDBCondition *condition = [AWSDynamoDBCondition new];
    AWSDynamoDBAttributeValue *attribute = [AWSDynamoDBAttributeValue new];
    attribute.N = @"400";
    condition.comparisonOperator = AWSDynamoDBComparisonOperatorEQ;

    NSDictionary *scanFilter = @{@"lat":
                                     @{@"AttributeValueList":attribute,
                                       @"ComparisonOperator":@1}
                                 };
    scanExpression.scanFilter = scanFilter;

解决方案

You can use it as follows:

AWSDynamoDBCondition *condition = [AWSDynamoDBCondition new];
AWSDynamoDBAttributeValue *attribute = [AWSDynamoDBAttributeValue new];
attribute.N = @"400";
condition.attributeValueList = @[attribute];
condition.comparisonOperator = AWSDynamoDBComparisonOperatorEQ;
scanExpression.scanFilter = @{@"lat": condition};

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