如何在每個循環內的主要查詢中運行輔助查詢

Question

如何修改我的代碼以允許我在每個循環中運行第二個查詢？

現在我已經註釋掉了第二個查詢，因爲我確定我需要在刪除斜槓之前進行一些更改。

<?php 

$mysqli = new mysqli('LOGIN DETAILS HERE'); 

if ($mysqli->connect_error) { 
    die('Connect Error: ' . $mysqli->connect_error); 
} 

$query = "SELECT * FROM toptips WHERE userid = 2"; 
$result = $mysqli->query($query); 

while($row = $result->fetch_array()) 
{ $rows[] = $row; } 

foreach($rows as $row) { 

    $id = $row['id']; 
    echo $row['time'] . " " . $row['course'] . " - " . $row['horse'] . " " . $row['description'] ."<br/>"; 

     // second query here 
    // $query2 = "SELECT likes FROM Likes_table WHERE id = $id"; 
    // $result = $mysqli->query($query2); 
    // while($row = $result->fetch_assoc()){ 
    // echo $row['likes'] . '<br />'; 
    // } 

} 

?> 

Answer 1

更好地利用INNER JOIN：

SELECT 
    toptips.*, 
    Likes_table.likes 
FROM 
    toptips 
INNER JOIN 
    Likes_table 
ON 
    Likes_table.id=toptips.id 
WHERE 
    toptips.userid = 2 

這將節省您大量的資源被去除內循環。