檢索值

Question

我已經陣列下面

Array ( 
     [0] => Array ( 
        [user_id] => 2 
        ) 
     [1] => Array (
        [user_id] => 4 
        ) 
     ) 

給出我需要選擇這些用戶ID的HTML表 來從數據庫和顯示數據我想這

foreach($prevUser as $key => $value){ 

     print_r($value); 
    } 

和接收這不是數值

Array ([user_id] => 2) Array ([user_id] => 4) 

如何獲取用戶ID

Answer 1

你可以像下面那樣獲得用戶，並且首先使用兩種方式觸發查詢。

foreach($prevUser as $key => $value){ 
    $user_id = $value['user_id']; 
    //write your query here like "select * from user where id = $user_id"; 
    print_r($value); 
} 

第二和正確的方法是

$userIds = []; 
foreach($prevUser as $key => $value){ 
    $userIds[] = $value['user_id']; 
} 

// stores all user_id on single array and then fire query like below 

//write your query here like "select * from user where id IN $userIds"; 

我寧願代替第二種方式第一種方式。我希望這有助於全力爲您

Answer 2

您可以使用$user_ids = array_column($prevUser, 'user_id');

$ user_ids是這樣的user_id數組[2,4]，那麼你可以像這樣的foreach遍歷它，

foreach($user_ids as $user_id) 
{ 
    echo $user_id; 
} 

Answer 3

<?php 
$array = Array(
    0 => Array(
     user_id => 2 
    ), 
    1 => Array(
     user_id => 4 
    ) 
); 
foreach ($array as $key => $value) { 
    $user_id = $value['user_id']; 
    echo $user_id; 
    echo "<br>"; 
} 
?>