<?php
    /**該P(yáng)HP文件為了連接數(shù)據(jù)庫方便
     * 為連接數(shù)據(jù)庫提供靜態(tài)方法
     */
    header("Content-type: text/html;charset=utf-8");
    class DBHelper {
        static $sqlName = "127.0.0.1";
        static $userName = "root";
        static $passWord = "123456";
        static $dbName = "test";
        //連接數(shù)據(jù)庫
        static function dbConn() {
            $conn = mysqli_connect(self::$sqlName, self::$userName,
                    self::$passWord, self::$dbName);
            if ($conn == false) {
                echo "<script>alert('數(shù)據(jù)庫連接失敗')</script>";
            }
            //設(shè)置連接對(duì)象編碼
            mysqli_query($conn, "set names utf8");
            return $conn;
        }
        //查詢數(shù)據(jù)
        //param1:查詢類型，param2:執(zhí)行語句
        //param1參數(shù)類型：  0單個(gè)數(shù)組，1多個(gè)數(shù)組。
        static function select($state, $mysql):array {
            $conn = self::dbConn(); //獲得連接對(duì)象
            $sql = $mysql;
            $query = mysqli_query($conn, $sql);
            if ($state == 1) {
                $result = mysqli_fetch_all($query,MYSQLI_ASSOC);
            } else {
                $result = mysqli_fetch_assoc($query);
            }
            // 釋放結(jié)果集
            mysqli_free_result($query);
            self::dbClose($conn); //釋放連接對(duì)象
            if ($result == null) { //如果結(jié)果為空，則返回空數(shù)據(jù)集
                return array();
            }
            return $result;
        }
        //增加、刪除、修改數(shù)據(jù)
        //param1:執(zhí)行類型；param2:執(zhí)行語句
        //param1參數(shù)類型：1增加，2修改，3刪除。
        static function sqlHelper($state, $mysql):int {
            $conn = self::dbConn(); //獲得連接對(duì)象
            $sql = $mysql;
            $query = mysqli_query($conn, $sql);
            //判斷狀態(tài)，做出相應(yīng)提示。
            //$sts = $state==3?"刪除":($state==2?"修改":($state==1?"增加":$state));
            self::dbClose($conn); //釋放連接對(duì)象
            if ($query){
                return 1;  //有內(nèi)容變化
                //return $sts."成功";
            }
            else{
                return 0;  //無內(nèi)容變化
                //return $sts."失敗";
            }
        }
        //關(guān)閉連接
        static function dbClose($conn) {
            $conn ->Close();
        }
    }
?>

//查詢單個(gè)數(shù)據(jù)
$select = DBHelper ::select(0, "select * from XXX where xx = '$xx'");
//查詢多個(gè)數(shù)據(jù)
$selectAll = DBHelper ::select(1,"select * from XXX");
//添加數(shù)據(jù)
$insert = DBHelper ::sqlHelper(1, "insert into XXX (xx,xx,xx) values ('$xx','$xx','$xx')");
//修改數(shù)據(jù)
$update = DBHelper ::sqlHelper(2, "update XXX set xx = '$xx',xx = '$xx',xx = '$xx', where xx = '$xx'");
//刪除數(shù)據(jù)
$delete = DBHelper ::sqlHelper(3, "delete from XXX where xx = '$xx'");