php去重复

<?php
// 原始数组
$array = array(1, 2, 2, 3, 4, 4, 5);

// 使用array_unique函数去重
$uniqueArray = array_unique($array);

print_r($uniqueArray);
?>

<?php
// 连接数据库
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database";

$conn = new mysqli($servername, $username, $password, $dbname);

if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 查询重复的邮箱地址
$sql = "SELECT email FROM users GROUP BY email HAVING COUNT(email) > 1";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
        $email = $row["email"];
        
        // 删除重复的记录，保留id最小的记录
        $deleteSql = "DELETE FROM users WHERE email = '$email' AND id NOT IN (SELECT MIN(id) FROM users WHERE email = '$email')";
        $conn->query($deleteSql);
    }
}

$conn->close();
?>