JSON 解码文件中的元素

嗨，我目前正在研究剥离一个 json 文件并将元素放入数据库中，使用以下代码在 json 文件中有 26 个条目我已经能够映射大多数条目，但现在处于 json 中的某些元素仅出现在某些条目中的位置，例如前 2 个条目中的标签具有名称和cirrushq_id字段，但来自第 3 个条目只有一个 aws：autoscaling：groupName 在前 2 个条目中不存在，所以我的问题实际上是如何修改 php，以便它考虑到可能没有每个条目的名称或 id 并且随后不会中断？

这是 PHP

<?php 

$con=mysqli_connect("localhost","root","","json_map");
$response = array(); 
$res=array(); 
$json = file_get_contents('C:'Users'Richard'Desktop'test.json'); 
if($json!=null){ 
$decoded=json_decode($json,true); 
//$decode= var_dump($decoded); 
//$ss=$decode["array"]; 
//echo $decoded['number']; 
if(is_array($decoded["configurationItems"])) 
{ 
foreach($decoded["configurationItems"] as $configurationItems) 
//for($i=0;$i>sizeof($decoded["configurationItems"]);$i++) 
 { 


$Name=$configurationItems["tags"]["Name"]; 
echo "Name:",$Name,"<br />"; 

$cirrushq_id=$configurationItems["tags"]["cirrushq_id"]; 
echo "cirrushq_id:",$cirrushq_id,"<br />"; 
$awsautoscalinggroupName= $configurationItems["tags"]["aws:autoscaling:groupName"]; 
 echo "aws:autoscaling:groupName:",$awsautoscalinggroupName,"<br />"; 



$result = mysqli_query($con, "INSERT INTO     tag(name, cirrushq_id, aws_autoscaling_group_name)

VALUES('$Name','$cirrushq_id', '$awsautoscalinggroupName')")or die("Insert Failed ".((is_object($con)) ? mysqli_error($con) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)));; 
}// check if row inserted or not 
if ($result) { 
    // successfully inserted into database 
    $response["code"] = 1; 
    $response["message"] = "successfully stored tags "; 
    // echoing JSON response 
    echo json_encode($response); 
} else { 
    // failed to insert row 
    $response["code"] = 2; 
    $response["message"] = "Oops! An error occurred."; 
    // echoing JSON response 
    echo json_encode($response); 
} 
} 
} 

  ?> 

和 JSON

 {  
 "fileVersion":"1.0",
 "configurationItems":[  
   {  
     "configurationItemVersion":"1.0",
     "configurationItemCaptureTime":"2014-12-05T10:22:51.751Z",
     "configurationStateId":1,
     "relatedEvents":[  ],
     "awsAccountId":"",
     "configurationItemStatus":"ResourceDiscovered",
     "resourceId":"",
     "ARN":"",
     "awsRegion":"us-east-1",
     "availabilityZone":"us-east-1b",
     "configurationStateMd5Hash":"",
     "resourceType":"AWS::EC2::Instance",
     "resourceCreationTime":"2014-01-06T10:37:37.000Z",
     "tags":{  
        "Name":"dbn.prod-us.wordeo.com",
        "cirrushq_id":"instance_20"
     },

与上述第二次进入

第 3 个条目与标签相同，如下所示

"tags":{  
        "aws:autoscaling:groupName":"ES-PROD-US-03-01-14"
     },

根据答案使用 ISSET 方法

<?php 

$con=mysqli_connect("localhost","root","","json_map");
$response = array(); 
$res=array(); 
$json = file_get_contents('C:'Users'Richard'Desktop'test.json'); 
if($json!=null){ 
$decoded=json_decode($json,true); 
//$decode= var_dump($decoded); 
//$ss=$decode["array"]; 
//echo $decoded['number']; 
if(is_array($decoded["configurationItems"])) 
{ 
foreach($decoded["configurationItems"] as $configurationItems) 
//for($i=0;$i>sizeof($decoded["configurationItems"]);$i++) 
$tags=$configurationItems["tags"];
if(isset($tags["Name"]) && isset($tags["cirrushq_id"])){
$Name=$tags["Name"]; 
echo "Name:",$Name,"<br />"; 
$cirrushq_id=$tags["cirrushq_id"]; 
echo "cirrushq_id:",$cirrushq_id,"<br />"; 
$awsautoscalinggroupName= isset($tags["aws:autoscaling:groupName"]) ?
                              $tags["aws:autoscaling:groupName"] : ''; 
echo "aws:autoscaling:groupName:",$awsautoscalinggroupName,"<br />"; 
$result = mysqli_query($con, "INSERT INTO tag(name, cirrushq_id, aws_autoscaling_group_name)
        VALUES('$Name','$cirrushq_id', '$awsautoscalinggroupName')"); 
}// check if row inserted or not 
if ($result) { 
    // successfully inserted into database 
    $response["code"] = 1; 
    $response["message"] = "successfully stored tags "; 
    // echoing JSON response 
    echo json_encode($response); 
} else { 
    // failed to insert row 
    $response["code"] = 2; 
    $response["message"] = "Oops! An error occurred."; 
    // echoing JSON response 
    echo json_encode($response); 
} 
} 
} 

？>