ios - 发电机 : The attempted filter operation is not supported for the provided filter argument count

Question

我正在使用带有 Amazon Web Services 的 iOS SDK

我正在尝试使用以下代码发出扫描请求:

DynamoDBScanRequest *request = [[DynamoDBScanRequest alloc] initWithTableName:self.tableName];
DynamoDBCondition *condition = [[DynamoDBCondition alloc] init];
[condition setComparisonOperator:@"GT"];
NSString *key = [[alertView textFieldAtIndex:0] text];    //Returns NSString @"00610"

[request setScanFilterValue:condition forKey:key];

DynamoDBScanResponse *response = [self.dbClient scan:request];

我收到这个错误:

The attempted filter operation is not supported for the provided filter argument count

请有人帮忙解释一下这是怎么回事!!!!

Answer 1

Conditions 需要一个特定大小的 AttributeValueList 作为 Condition 名称，基于 Condition 的名称；此错误意味着您尝试将 GT(大于)与错误数量的 attributeValues 一起使用。大于需要 1 个属性值，因此您可能提供 0 或 2。

以下是其他条件，以及它们需要的属性值的数量:

NOT_NULL     0  (exists)
NULL         0  (not exists)
EQ           1  (equal) 
NE           1  (not equal)
IN           1  (exact matches)
LE           1  (less than or equal to)
LT           1  (less than)
GE           1  (greater than or equal to)
GT           1  (greater than)
CONTAINS     1  (substring or value in a set)
NOT_CONTAINS 1  (absence of a substring or absence of a value in a set)
BEGINS_WITH  1  (a substring prefix)
BETWEEN      2  (between)