如何在PHP MySQL的恆定執行查詢

Question

在執行查詢得到這個錯誤「錯誤更新記錄：您在您的SQL語法錯誤」

$conn = new mysqli($servername, $username, $password, $dbname); 
$sql = "SET @a:=0;UPDATE registrations SET EXIBIT_NO=@a:=@a+1 ORDER BY GR_ID"; 

Answer 1

可以wrtie：

$result=mysqli_query($conn,$sql);

代碼示例：

<?php 
$servername = "localhost"; 
$username = "username"; 
$password = "password"; 
$dbname = "myDB"; 

// Create connection 
$conn = mysqli_connect($servername, $username, $password, $dbname); 
// Check connection 
if (!$conn) { 
    die("Connection failed: " . mysqli_connect_error()); 
} 

$sql = "SELECT id, firstname, lastname FROM MyGuests"; 
$result = mysqli_query($conn, $sql); 

if (mysqli_num_rows($result) > 0) { 
    // output data of each row 
    while($row = mysqli_fetch_assoc($result)) { 
     echo "id: " . $row["id"]. " - Name: " . $row["firstname"]. " " . $row["lastname"]. "<br>"; 
    } 
} else { 
    echo "0 results"; 
} 

mysqli_close($conn); 
?>