php 链接多个mysql

<?php
// 数据库1配置
$db1_config = [
    'host' => 'localhost',
    'user' => 'user1',
    'password' => 'password1',
    'database' => 'database1'
];

// 数据库2配置
$db2_config = [
    'host' => 'localhost',
    'user' => 'user2',
    'password' => 'password2',
    'database' => 'database2'
];

// 链接数据库1
$db1 = new mysqli($db1_config['host'], $db1_config['user'], $db1_config['password'], $db1_config['database']);
if ($db1->connect_error) {
    die("连接数据库1失败: " . $db1->connect_error);
}

// 链接数据库2
$db2 = new mysqli($db2_config['host'], $db2_config['user'], $db2_config['password'], $db2_config['database']);
if ($db2->connect_error) {
    die("连接数据库2失败: " . $db2->connect_error);
}

// 查询数据库1
$sql1 = "SELECT * FROM table1";
$result1 = $db1->query($sql1);
if ($result1->num_rows > 0) {
    while($row = $result1->fetch_assoc()) {
        echo "数据库1: " . $row["column_name"] . "<br>";
    }
} else {
    echo "数据库1没有结果";
}

// 查询数据库2
$sql2 = "SELECT * FROM table2";
$result2 = $db2->query($sql2);
if ($result2->num_rows > 0) {
    while($row = $result2->fetch_assoc()) {
        echo "数据库2: " . $row["column_name"] . "<br>";
    }
} else {
    echo "数据库2没有结果";
}

// 关闭连接
$db1->close();
$db2->close();
?>

$db1->set_charset("utf8");
$db2->set_charset("utf8");