Question

我正在为我的预订系统构建搜索引擎。我已成功设法构建一个查询一个数据库的搜索引擎，但我想知道如何使用相同的搜索引擎查询多个数据库。

第一个数据库（$ conn）包含以下内容：

设备
预订日期
开始时间
结束时间
注释

第二个数据库（$ conn2）包含以下内容： - 房间 - 预定日期 - 开始时间 - 时间结束 - 备注

我尝试执行以下操作，但是出现了以下错误消息：

警告：mysqli_num_rows（）期望参数1为mysqli_result，在第74行的C：\ xampp \ htdocs \ results.php中给出的布尔值

这是我的代码：

<?php

$server="localhost";
$username="root";
$password="";
$dbname="equipment";
$conn=mysqli_connect($server,$username,$password,$dbname);
$conn2=mysqli_connect($server,$username,$password,$dbname);

?>

<!doctype html>

<html>

<head> 

<link rel="stylesheet" type="text/css" href="resultsstyle.css">
<link rel="icon" href="Icon.jpg">

<title>Search</title>

</head>

<body>

<div class="header">

<img class="icon" src="Icon.jpg"> 
<div class="search">Search </div>

</div>

<div class="select">Results </div>



<?php

if (isset($_POST['submit-search'])){
    $search=mysqli_real_escape_string($conn,$_POST['search']);
    $sql="SELECT * FROM bookings WHERE equipment LIKE'%$search%' OR start_time LIKE '%$search%'OR end_time LIKE '%$search%'OR selected_date LIKE '%$search%'";
    $result=mysqli_query($conn, $sql);
    $queryResult=mysqli_num_rows($result);

    if(empty($_POST['search'])){
        echo '<span class="empty">Search box was empty. Please try again.</span>';
    }else{

    if($queryResult>0){
        while($row=mysqli_fetch_assoc($result)){
            echo "
<span class='e'>Equipment: <span class='first'>".htmlspecialchars($row['equipment'])."</span></span><br>
<span class='bd'>Booking Date: <span class='second'>".htmlspecialchars($row['selected_date'])."</span></span><br>
<span class='st'>Start Time: <span class='third'>".htmlspecialchars($row['start_time'])."</span></span><br>
<span class='et'>End Time: <span class='fourth'>".htmlspecialchars($row['end_time'])."</span></span><br>
<span class='n'>Notes: <span class='fifth'>".htmlspecialchars($row['notes'])."</span></span><br><br><br><br>
";
    }
        }else{
        echo "<span class='none'>No results were found.</span>";

}
}
}
?>

<?php

if (isset($_POST['submit-search'])){
    $search=mysqli_real_escape_string($conn2,$_POST['search']);
    $sql="SELECT * FROM bookings2 WHERE room LIKE'%$search%' OR start_time LIKE '%$search%'OR end_time LIKE '%$search%'OR selected_date LIKE '%$search%'";
    $result=mysqli_query($conn2, $sql);
    $queryResult=mysqli_num_rows($result);

    if(empty($_POST['search'])){
        echo '<span class="empty">Search box was empty. Please try again.</span>';
    }else{

    if($queryResult>0){
        while($row=mysqli_fetch_assoc($result)){
            echo "
<span class='e'>Room: <span class='first'>".htmlspecialchars($row['room'])."</span></span><br>
<span class='bd'>Booking Date: <span class='second'>".htmlspecialchars($row['selected_date'])."</span></span><br>
<span class='st'>Start Time: <span class='third'>".htmlspecialchars($row['start_time'])."</span></span><br>
<span class='et'>End Time: <span class='fourth'>".htmlspecialchars($row['end_time'])."</span></span><br>
<span class='n'>Notes: <span class='fifth'>".htmlspecialchars($row['notes'])."</span></span><br><br><br><br>
";
}
    }else{
        echo "<span class='none'>No results were found.</span>";

}
}
}
?>

我拼命尝试了一切，但同样的错误信息不断出现。任何帮助，将不胜感激。谢谢

Answer 1

首先，我建议不要使用存储的过程语句，因为你对任何sql注入都是开放的。阅读更多相关信息here。
要回答您的问题，“如何使用相同的搜索引擎查询多个数据库”将是LEFT JOIN。有了这个，您可以在一个查询中加入两个或多个数据库。例如：SELECT d.*, db.* FROM database AS d LEFT JOIN database2 AS db ON d.booking_date = db.booking_date WHERE equipment = %search%。在这里，我选择了加入*和database的数据库中的所有内容（database2）在每个属性中共有的属性（booking_date）。因此，您的查询如下所示：SELECT b.*bk.* FROM bookings AS b LEFT JOIN bk AS bookings2 ON b.start_time = bk.start_time WHERE (b.equipment OR bk.rooms) LIKE'%$search%' OR start_time LIKE '%$search%'OR end_time LIKE '%$search%'OR selected_date LIKE '%$search%'您可以阅读有关LEFT JOIN here.

的更多信息

PHP-构建搜索引擎（查询多个数据库）

1 个答案: