PHP：在更新json文件時，首先匹配條目。如果匹配，比替換/更新，否則寫

Question

最近即時通訊嘗試與我的高等教育項目通過PHP的JSON數據。但是，我在管理/更新JSON文件時掛機。

讓我介紹你的整個場景：

它的一款入門基礎的項目，所有項目必須在JSON文件（.json）來保存，格式是：

[{"Name":"xyz","UID":"1234","RDate":"11122014","ReLogin":"true","LTime":"1e3","Passive":"false"},{"Name":"abc","UID":"5678","RDate":"01102014","ReLogin":"true","LTime":"1e3","Passive":"false"},......] 

現在，我必須做的是：當一個新條目發送給PHP時，首先根據一些標準查找匹配條目，如name，uid,rdate。 如果匹配成功，比替換/更新文件中的整個條目 如果匹配未找到，則將新條目添加/寫入文件。

要做到這一點，我目前正試圖用這些一串代碼：

1）`函數chkEntry（$ UID，$輸入）

$file='file.json'; 
$s[]=$entry;$match=0; 
global $RESP; 
if(0==filesize($file)){ 
    return true; 
}else{ 
    $data=json_decode(file_get_contents($file),true); 
    foreach($data as $keyD=>$valD){ 
    foreach($s as $keyS=>$valS){ 
     if($valD["Name"]!=$valS["Name"]||$valD["UID"]!=$valS["UID"]||$valD["RDate"]!=$valS["RDate"]){ // here `RDate` is always unique, so I can use it for the matching process 
     $match=0; 
     }else{ 
     $match=1; 
     } 
    } 
    } 
    if($match==1){return false;}else{return true;} 
} 

這chkEntry總是返回false :( 同時，我不知道如何更換INT該文件的同時進入，如果發現匹配

修訂chkEntry function：匹配標準僅限於單僅參數[uid]。如果找到匹配項，則刪除整個條目並將return true設置爲addEntry function，以便addEntry添加新條目。但不幸的是，這個function也未按預期工作。

function chkEntry($uid,$entry){ 
    $file='file.json'; 
    $data=json_decode(file_get_contents($file),true); 
    foreach($data as $keyD=>$valD){ 
    if($valD["uid"]==$entry["uid"]){ 
     unset($data[$keyD]); //delete the entry, if matched 
     file_put_contents($file,json_encode($data)); 
     return true; 
    } 
    } 
    return true; 
} 

2）`函數的addEntry（$ UID，$輸入）

global $RESP; 
$ready=false; 
$file='file.json'; 
if(addFile($uid)){ //`function addFile`, if file not exists, than create an blank file 
    $data=json_decode('file.json',true); 
    unset($file); 
    if(chkEntry($uid,$entry)){ //`function chkEntry`, match the entry 
    $data[]=$entry; 
    file_put_contents('file.json',json_encode($data)); 
    unset($data); 
    }else{ 
    $RESP["entry"]="This entry is already exists into Database"; 
    } 
    $ready=true; 
}else{ 
    $RESP["err"]="We are unable to add the entry right now. Please try after some time!"; 
} 
if($ready){ 
    if(!isset($RESP["entry"])){$RESP["entry"]="for evaluatuion";} 
    return true; 
}else{ 
    $RESP["err"]="Something went wrong! Please try to add this later."; 
    return false; 
} 

3）

$entry=array("Name"=>$_POST["name"],"UID"=>$_POST["uid"],"RDate"=>$_POST["rdate"],"ReLogin"=>$_POST["relogin"],"LTime"=>$_POST["ltime"],"Passive"=>$_POST["passive"]); 
addServer($uid,$entry); 

所以，我的問題是：

如何發現/匹配功能應該進行管理，使其return true如果匹配發現，否則return false和IF MATCH FOUND，比如何重新將整個條目放入/更新到文件中。

例如：如果新條目

{"Name":"try","UID":"1111","RDate":"12122014","ReLogin":"`true","LTime":"1e3","Passive":"false"} 

不是先匹配現有條目，比廣告它的文件。

如果新的條目：（基於name，uid，rdate）

{"Name":"xyz","UID":"2222","RDate":"15122014","ReLogin":"true","LTime":"1e3","Passive":"false"} //match found, based on `name` 

OR

{"Name":"nws","UID":"1234","RDate":"19122014","ReLogin":"true","LTime":"1e3","Passive":"false"} //match found, based on `uid` 

OR

{"Name":"nws","UID":"2222","RDate":"11122014","ReLogin":"true","LTime":"1e3","Passive":"false"} //match found, based on `rdate` 

不是更新/更換舊條目{"Name":"xyz","UID":"1234","RDate":"11122014","ReLogin":"true","LTime":"1e3","Passive":"false"}用它。

幫我PLZ .....

感謝&問候

Answer 1

下面是我如何去做（減去錯誤信息），將所有事情簡化爲一個函數。

define('JSON_FILE', 'file.json'); 

function addEntry($newEntry) 
{ 
    // flag to indicate whether an update was made or not; 
    // flag is by default set to false to assume no update was made 
    $update = false; 
    // retrieve list of current entries 
    if (file_exists(JSON_FILE)) { 
     $entries = json_decode(file_get_contents(JSON_FILE), true); 
    } 
    // if there are entries, look for a match 
    if (!empty($entries)) { 
     foreach ($entries as $i => $entry) { 
      // if match IS found... 
      if ($entry["Name"] == $newEntry["Name"] || 
       $entry["UID"] == $newEntry["UID"] || 
       $entry["RDate"] == $newEntry["RDate"]){ 
       // update/replace existing entry with new entry 
       $entries[$i] = $newEntry; 
       // turn on flag to indicate that an update was made 
       $update = true; 
       // no need to keep searching any further, so quit loop 
       break; 
      } 
     } 
    // otherwise if there no entries, create an empty list 
    } else { 
     $entries = array(); 
    } 
    // if no update was made i.e. no match was found, then it means a new entry needs to be added 
    if (!$update) { 
     // add new entry 
     $entries[] = $newEntry; 
    } 
    // save list of entries 
    file_put_contents(JSON_FILE, json_encode($entries)); 
} 

$entry = array(
    "Name" => $_POST["name"], 
    "UID" => $_POST["uid"], 
    "RDate" => $_POST["rdate"], 
    "ReLogin" => $_POST["relogin"], 
    "LTime" => $_POST["ltime"], 
    "Passive" => $_POST["passive"] 
); 

addEntry($entry); 

Answer 2

chkEntry很可能失敗，因爲json_decode（）的錯誤了。 Json_decode在錯誤時返回null，並且在php $x = null; $x[1] === NULL中始終爲真; null $ x上的所有下標值都將爲null，因此彼此相等。