php csv 导出

<?php
header('content-type:text/html;charset=utf-8');

$mysqli = new mysqli('localhost', 'root', '', 'c');
if ($mysqli->errno) {
    die('Connect Error' . $mysqli->error);
}
$mysqli->set_charset('UTF8');

export_csv();

function export_csv() {
    $filename = date('YmdHis') . ".csv";//文件名
    header("Content-type:text/csv");
    header("Content-Disposition:attachment;filename=" . $filename);
    header('Cache-Control:must-revalidate,post-check=0,pre-check=0');
    header('Expires:0');
    header('Pragma:public');
    echo array_to_string(get_export_data());
}

function i($strInput) {
    return iconv('utf-8', 'gb2312', $strInput);//页面编码为utf-8时使用，否则导出的中文为乱码
}

function array_to_string($result) {
    if (empty($result)) {
        return i("没有符合您要求的数据！");
    }

    //表头
    $data = iconv('utf-8', 'gb2312', "kh_name,kh_address") . "\r\n";

    $size_result = sizeof($result);

    for ($i = 0; $i < $size_result; $i++) {
        $data .= i($result[$i]['kh_name']) . ',' . i($result[$i]['kh_address']) . "\n";
    }
    return $data;
}

function get_export_data() {

    $sql = "SELECT kh_name,kh_address FROM bs_kehu";

    global $mysqli;
    $result = $mysqli->query($sql);

    $res = array();
    $i = 0;
    while ($row = $result->fetch_array(MYSQLI_ASSOC)) {
        $res[$i]['kh_name'] = $row['kh_name'];
        $res[$i]['kh_address'] = $row['kh_address'];
        $i++;
    }
    return $res;
}