构建客户关系管理功能的企业资源计划（ERP）系统的PHP开发

<?php
// 数据库连接配置
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "erp_crm";

// 连接数据库
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接是否成功
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}
?>

function addCustomer($name, $phone, $email) {
    global $conn;
    $sql = "INSERT INTO customer (name, phone, email) VALUES ('$name', '$phone', '$email')";
    if ($conn->query($sql) === TRUE) {
        echo "客户添加成功";
    } else {
        echo "客户添加失败: " . $conn->error;
    }
}

function addContact($customerId, $name, $position, $phone, $email) {
    global $conn;
    $sql = "INSERT INTO contact (customer_id, name, position, phone, email) VALUES ('$customerId', '$name', '$position', '$phone', '$email')";
    if ($conn->query($sql) === TRUE) {
        echo "联系人添加成功";
    } else {
        echo "联系人添加失败: " . $conn->error;
    }
}

function addDeal($customerId, $date, $amount) {
    global $conn;
    $sql = "INSERT INTO deal (customer_id, date, amount) VALUES ('$customerId', '$date', '$amount')";
    if ($conn->query($sql) === TRUE) {
        echo "交易添加成功";
    } else {
        echo "交易添加失败: " . $conn->error;
    }
}

function addActivity($customerId, $name, $date) {
    global $conn;
    $sql = "INSERT INTO activity (customer_id, name, date) VALUES ('$customerId', '$name', '$date')";
    if ($conn->query($sql) === TRUE) {
        echo "活动添加成功";
    } else {
        echo "活动添加失败: " . $conn->error;
    }
}

function addNote($customerId, $content) {
    global $conn;
    $sql = "INSERT INTO note (customer_id, content) VALUES ('$customerId', '$content')";
    if ($conn->query($sql) === TRUE) {
        echo "备注添加成功";
    } else {
        echo "备注添加失败: " . $conn->error;
    }
}

// 添加客户
addCustomer("John Doe", "123456789", "john@example.com");

// 根据客户ID添加联系人
$customerId = 1;
addContact($customerId, "Jane Smith", "Manager", "987654321", "jane@example.com");