php - 当我使用嵌套 while 循环从另一个表获取数据时，while 循环只显示一条记录

Question

我有案件经理表，我在其中插入法院表 ID 作为外键。我想从两个表中获取记录。使用嵌套 while 循环时，它只显示一行数据。

$id = $_SESSION['id'];
$query1 = "SELECT * from `case_manager` where user_id = '$id' ";
$result1 = mysqli_query($conn, "$query1");
while($row = mysqli_fetch_array($result1, MYSQLI_ASSOC)) {
    $Status = $row['status'];
    $id = $row['id'];
    $case_type = $row['case_type'];
    $court_id = $row['court_id'];
    $query2 = "SELECT * from `case_type` where case_id = '$case_type'";
    if($result1 = mysqli_query($conn, "$query2")) {
        while($row2 = mysqli_fetch_array($result1, MYSQLI_ASSOC)) {
            echo $row2['case_name'];
        }
    }
} 

Answer 1

因为你正在覆盖你 $result1 将内部查询结果更改为 $result2 然后尝试

$id = $_SESSION['id'];
$query1 ="SELECT * from `case_manager` where user_id = '$id' "; 
$result1 = mysqli_query($conn , "$query1");
while ($row = mysqli_fetch_array($result1 ,MYSQLI_ASSOC)) {
  $Status=$row['status'];
  $id = $row['id'];
  $case_type = $row['case_type'];
  $court_id = $row['court_id'];
  $query2 ="SELECT * from `case_type` where case_id = '$case_type'"; 
  if($result2 = mysqli_query($conn , "$query2")){;
    while ($row2 = mysqli_fetch_array($result2 ,MYSQLI_ASSOC)) {
      echo $row2['case_name'];
    } 
  }
}