PHP简单封装MysqlHelper类

MysqlHelper.class.php

<?php

/**
 * Mysql数据帮助类
 */
class MysqlHelper
{
    function __construct()
    {
        if(isset($conn)){return;}
        //创建连接对象
        $this->conn=@mysql_connect($this->host,$this->uid,$this->pwd);
        if(!$this->conn){
            die('连接数据库失败：'.mysql_error());
        }

        //选择数据库和设置编码
        mysql_select_db($this->db,$this->conn);
        mysql_query('set names utf8');
    }

    private $conn;
    private $host='localhost';
    private $uid='root';
    private $pwd='1234';
    private $db='test2';

    /**
     * [execute_dql 执行查询语句]
     * @param [string] $sql [查询语句]
     */
    public function execute_dql($sql)
    {
        $result = mysql_query($sql,$this->conn) or die('执行DQL语句时出错：'.mysql_error());
        return $result;
    }

    /**
     * [execute_dml 执行增删改语句]
     * @param [string] $sql [查询语句]
     * @return [失败返回-1,无影响返回0,成功返回受影响的行数]
     */
    public function execute_dml($sql)
    {
        $result = mysql_query($sql,$this->conn) or die('执行DML语句时出错：'.mysql_error());
        if(!$result){
            return -1; //操作失败
        }else{
            return mysql_affected_rows($this->conn);
        }
    }

    /**
     * [show_table_data 显示表数据]
     * @param  [string] $tableName [表名]
     * @return [string]            [HTML表格]
     */
    public function show_table_data($tableName)
    {
        $result = $this->execute_dql("select * from $tableName");

        $this->show_table($result);

        mysql_free_result($result);
        mysql_close($this->conn);
    }

    /**
     * [show_table_info 显示表结构]
     * @param  [string] $tableName [表名]
     * @return [string]            [HTML表格]
     */
    public function show_table_info($tableName)
    {
        $result = $this->execute_dql("desc $tableName");

        $this->show_table($result);

        mysql_free_result($result);
        mysql_close($this->conn);
    }

    /**
     * [show_table 拼接表格]
     * @param  [resource] $result [结果集]
     * @return [string]         [HTML]
     */
    public function show_table($result)
    {
        //显示表头信息：
        echo "<br/>数据表：".mysql_field_table($result, 0)."  总行数：".mysql_num_rows($result);
        $tableData="<table border='1' cellpadding='5'><tr>";
        $fieldsCount = mysql_num_fields($result);
        for ($i=0; $i <$fieldsCount; $i++) {
            $tableData.= "<th>".mysql_field_name($result, $i)."</th>";
        }
        $tableData.="</tr>";

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

        echo $tableData;
    }
}

?>

调用示例：

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

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

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

//实例化MysqlHelper对象
$execute = new MysqlHelper();

// 增
$sql = "insert into userinfo(uName,uAge,uPwd) values('测试04',18,MD5('1234'));";
// 删
// $sql = "delete from userinfo where id=20";
// 改
// $sql = "update userinfo set uAge=19 where Id=21";

//对数据执行DML操作
$returnNum = $execute->execute_dml($sql);
if ($returnNum ==-1) {
    echo "操作失败 :(";
} else {
    echo "操作成功:) <b style='color:red;'>".$returnNum."</b>行受影响<br/>";
}


//显示表信息：
$execute->show_table_info("userinfo");

//显示表数据：
$execute->show_table_data("userinfo");


?>