Ios 如何在swift中编写dynamodb查询以获取具有特定分区键的所有值
我无法找到用swift编写dynamodb查询以获取具有特定分区键的结果的方法 例如,假设我的分区键是“bigCompany”,排序键是“email”。现在,我想获取所有电子邮件,其“大公司”名称为“xyz” 作为参考,我的代码结构与下面的加载函数非常相似。但是这个函数使用Ios 如何在swift中编写dynamodb查询以获取具有特定分区键的所有值,ios,swift,amazon-dynamodb,Ios,Swift,Amazon Dynamodb,我无法找到用swift编写dynamodb查询以获取具有特定分区键的结果的方法 例如,假设我的分区键是“bigCompany”,排序键是“email”。现在,我想获取所有电子邮件,其“大公司”名称为“xyz” 作为参考,我的代码结构与下面的加载函数非常相似。但是这个函数使用.load来获取一个值,而不是查询。基本上,我需要找到一种方法来调用dynamodbobbjectmapper.query(),以满足我上面提到的约束条件。任何帮助都将不胜感激 func getTableRow() {
.load
来获取一个值,而不是查询。基本上,我需要找到一种方法来调用dynamodbobbjectmapper.query()
,以满足我上面提到的约束条件。任何帮助都将不胜感激
func getTableRow() {
let dynamoDBObjectMapper = AWSDynamoDBObjectMapper.defaultDynamoDBObjectMapper()
//tableRow?.UserId --> (tableRow?.UserId)!
dynamoDBObjectMapper .load(DDBTableRow.self, hashKey: (tableRow?.UserId)!, rangeKey: tableRow?.GameTitle) .continueWithExecutor(AWSExecutor.mainThreadExecutor(), withBlock: { (task:AWSTask!) -> AnyObject! in
if (task.error == nil) {
if (task.result != nil) {
let tableRow = task.result as! DDBTableRow
self.hashKeyTextField.text = tableRow.UserId
self.rangeKeyTextField.text = tableRow.GameTitle
self.attribute1TextField.text = tableRow.TopScore?.stringValue
self.attribute2TextField.text = tableRow.Wins?.stringValue
self.attribute3TextField.text = tableRow.Losses?.stringValue
}
} else {
print("Error: \(task.error)")
let alertController = UIAlertController(title: "Failed to get item from table.", message: task.error!.description, preferredStyle: UIAlertControllerStyle.Alert)
let okAction = UIAlertAction(title: "OK", style: UIAlertActionStyle.Cancel, handler: { (action:UIAlertAction) -> Void in
})
alertController.addAction(okAction)
self.presentViewController(alertController, animated: true, completion: nil)
}
return nil
})
}
我明白了。它们的关键是正确使用keyConditionExpression。下面是我的答案
let queryExpression = AWSDynamoDBQueryExpression()
queryExpression.keyConditionExpression = "#bigCompany = :bigCompany"
queryExpression.expressionAttributeNames = ["#bigCompany": "bigCompany",]
queryExpression.expressionAttributeValues = [":bigCompany" : self.bigCompany,]
dynamoDBObjectMapper.query(Requests.self, expression: queryExpression) .continue(with: AWSExecutor.immediate(), with: { (task:AWSTask!) -> AnyObject! in
//If added successfully
if((task.result) != nil) {
let results = task.result! as AWSDynamoDBPaginatedOutput
print(results.items)
}
else {
//do error checking here
}
})
我明白了。它们的关键是正确使用keyConditionExpression。下面是我的答案
let queryExpression = AWSDynamoDBQueryExpression()
queryExpression.keyConditionExpression = "#bigCompany = :bigCompany"
queryExpression.expressionAttributeNames = ["#bigCompany": "bigCompany",]
queryExpression.expressionAttributeValues = [":bigCompany" : self.bigCompany,]
dynamoDBObjectMapper.query(Requests.self, expression: queryExpression) .continue(with: AWSExecutor.immediate(), with: { (task:AWSTask!) -> AnyObject! in
//If added successfully
if((task.result) != nil) {
let results = task.result! as AWSDynamoDBPaginatedOutput
print(results.items)
}
else {
//do error checking here
}
})