錯誤在PHP mysqli_fetch_array（）

Question

<?php 

    $connection = mysqli_connect("localhost", "gari" , "gari" , "onlinemarket"); 

    $call = "SELECT * FROM products WHERE id ='". 4 ."'"; 
    $result = mysqli_query($connection , $call); 

    while ($row = mysqli_fetch_array($result)) { 

     $call = "UPDATE products SET stock = '". 666 ."' WHERE id ='". 4 ."'"; 
     $result = mysqli_query($connection , $call); 

    } 
    mysqli_close($connection); 
?> 

真正的問題是在$row = mysqli_fetch_array($result)，收到這樣的：

mysqli_fetch_array（）預計參數1被mysqli_result，在C中給出布爾 ：\ XAMPP \ htdocs中\第12行的tiendaonline \ php \ prueba.php我不知道 知道如何使用mysqli_error（）來獲取錯誤。

謝謝。

Answer 1

試試這個，

<?php 

    $connection = mysqli_connect("localhost", "gari" , "gari" , "onlinemarket"); 

    $call = "SELECT * FROM products WHERE id ='4'"; 
    $result = mysqli_query($connection , $call); 

    while ($row = mysqli_fetch_array($result)) 
    { 

     $call1 = "UPDATE products SET stock = '666' WHERE id ='4'"; 
     $result1 = mysqli_query($connection , $call1); 

    } 
    mysqli_close($connection); 

?> 

希望這有助於。

Answer 2

看起來像內循環取代$result，while循環沒有意義，如果你不使用$row內循環。請嘗試以下代碼

<?php 

$connection = mysqli_connect("localhost", "gari" , "gari" , "onlinemarket"); 

$call = "SELECT * FROM products WHERE id ='". 4 ."'"; 
$result = mysqli_query($connection , $call); 

while ($row = mysqli_fetch_array($result)) 
{ 

$call = "UPDATE products SET stock = '". 666 ."' WHERE id ='". 4 ."'"; 
$resultUpdate = mysqli_query($connection , $call); 

} 
mysqli_close($connection); 
?> 

如果您只是需要更新記錄，則不需要選擇查詢，然後使用以下代碼。

$call = "UPDATE products SET stock = '". 666 ."' WHERE id ='". 4 ."'"; 
$resultUpdate = mysqli_query($connection , $call); 
mysqli_close($connection); 

Answer 3

嘗試這樣，

$resultUpdate = mysqli_query($connection, $call) 
     or die("Error: " . mysqli_error($connection)); 

Answer 4

在while循環，要重設$結果和由於在循環中你正在做一個更新查詢數據庫，輸出將是無論是真或假。 並且在循環的下一次迭代中，mysqli_fetch_array找不到任何要迭代的內容。嘗試這樣的：

. 
. 
. 
$result_select = mysqli_query($connection , $call); 
while ($row = mysqli_fetch_array($result)) 
{ 

    $call = "UPDATE products SET stock = '". 666 ."' WHERE id ='". 4 ."'"; 
    $result_update = mysqli_query($connection , $call); 
}