嵌套的while循环不工作

Question

我正在开发一个web服务和android应用程序web服务是在PHP从MySQL数据库获取数据...我遇到的问题是，一些项目有多个细节，但我的代码是只为每个项目提供一个细节。我以JSON格式获取数据。

您可以检查此Here

这里是我的代码提前

function requiredData(){ 

    $db = $this->dbConnection(); 
    //$sql = "SELECT * FROM projects JOIN project_details ON projects.project_id=project_details.project_id"; 
    $sql = "SELECT * FROM projects"; 

    $queryResult = $db->query($sql); 

     if($queryResult->num_rows > 0){ 

      while($row = $queryResult->fetch_assoc()){ 

       $pid = $row['project_id']; 
       $detailsql = "SELECT * FROM project_details WHERE project_id=$pid"; 
       $sqlResult = $db->query($detailsql); 
       if($sqlResult->num_rows > 0){ 
        while ($d = $sqlResult->fetch_assoc()){ 
         $r = array(
          "project_id" => $d['project_id'], 
          "project_detail" => array(
           "work_done" => $d['project_detail'], 
           "payment_for_work" => $d['project_payment'], 
           "payment_status" => $d['project_payment_status'], 
           "detail_id" => $d['project_detail_id'] 
          ) 
         ); 
        } 
       } 
       $results[$row['project_name']] = array(
        "project_id" => $row["project_id"], 
        "project_start_date" => $row["project_start_date"], 
        "project_due_date" => $row["project_due_date"], 
        "project_currency" => $row["project_currency"], 
        "project_work_details" => $r 
       ); 


      } 
     } 
     return $results; 
} 

感谢您的帮助

Answer 1

的问题是在第二while循环。您正将数组分配到$r，并且每次都覆盖$r值。因此，我现在将数组赋值给另一个数组，所以它会变成2维数组，如下所示：

   while ($d = $sqlResult->fetch_assoc()){ 
        $r[] = array(
         "project_id" => $d['project_id'], 
         "project_detail" => array(
          "work_done" => $d['project_detail'], 
          "payment_for_work" => $d['project_payment'], 
          "payment_status" => $d['project_payment_status'], 
          "detail_id" => $d['project_detail_id'] 
         ) 
        ); 
       } 

现在你可以使用$r，它会有多个项目细节。