PHP基础封装简单的MysqliHelper类

MysqliHelper.class.php

<?php

/**
* MysqliHelper
* [面向对象的MysqliHelper的简单封装]
*/
class MysqliHelper
{
    private static $mysqli;
    private static $host='localhost';
    private static $uid='root';
    private static $pwd='1234';
    private static $dbName='test2';

    /**
     * [connect 创建连接]
     */
    public static function connect()
    {
        if(isset(self::$mysqli))return;
        self::$mysqli = new MySQLi(self::$host,self::$uid,self::$pwd,self::$dbName);
        !empty(self::$mysqli) or die("数据库连接失败：".self::$mysqli->connect_error);
        self::$mysqli->query("set names utf8");
    }

    /**
     * [execute_dml 执行增删改操作]
     * @param  [string] $sql [DML语句]
     * @return [int]      [操作成功返回受影响行数，否则返回-1]
     */
    public static function execute_dml($sql)
    {
        self::connect();
        $result = self::$mysqli->query($sql) or die('执行DML语句时出错：'.self::$mysqli->error);
        if (!$result) {
            return -1;
        } else {
            return self::$mysqli->affected_rows;
        }
    }

    /**
     * [execute_dql 执行查询操作]
     * @param  [string] $sql [DQL语句]
     * @return [mysqli_result]      [返回查询结果集]
     */
    public static function execute_dql($sql)
    {
        self::connect();
        $result = self::$mysqli->query($sql) or die('执行DQL语句时出错：'.self::$mysqli->error);
        return $result;
    }

    /**
     * [show_table_data 显示表数据]
     * @param  [string] $tableName [表名]
     * @return [string]            [HTML]
     */
    public static function show_table_data($tableName)
    {
        $result=self::execute_dql("select * from $tableName");
        //显示表头信息：
        echo "<br/>数据表：".$result->fetch_field()->table."  总行数：".$result->num_rows;
        $tableData="<table border='1' cellpadding='5'><tr>";
        $fieldsCount = $result->field_count;
        for ($i=0; $i <$fieldsCount; $i++) {
            $tableData.= "<th>".$result->fetch_field_direct($i)->name."</th>";
        }
        $tableData.="</tr>";

        //显示数据信息：
        while ($row = $result->fetch_object()) {
            $tableData.="<tr>";
            foreach ($row as $value) {
                $tableData.="<td>$value</td>";
            }
            $tableData.="</tr>";
        }
        $tableData.="</table>";

        $result->free();
        self::$mysqli->close();
        //或者 mysqli_close(self::$mysqli);
        echo $tableData;
    }

}
?>

 

调用示例:

<?php
header("Content-Type:text/html; charset=utf8");

//自定义MysqliHelper的测试与使用
//============================================

//引用自定义的MysqliHelper类
require_once "MysqliHelper.class.php";

// 查
// $sql = "select * from userinfo where id>8";
// 增
// $sql = "insert into userinfo(uName,uAge,uPwd) values('测试08',25,MD5('1234'));";
// 删
// $sql = "delete from userinfo where id=24";
// 改
$sql = "update userinfo set uAge=28 where Id=21";

//执行查询语句
// $result = MysqliHelper::execute_dql($sql);

//执行增删改语句
$result = MysqliHelper::execute_dml($sql);
if ($result==-1) {
    echo "操作失败:(";
} else {
    echo "操作成功：".$result."行受影响";
}

//显示表数据
MysqliHelper::show_table_data("userinfo");

?>