PHP数据库编程②自写PHP连接数据库并且操作数据库函数SQLtool_class.php

<?php

class SQLtool{
private $conn;
private $host="localhost";
private $user="root";
private $password="root1142495240";
private $db="123"; //指定所链接数据库
function SQLtool(){
$this->conn=mysql_connect($this->host,$this->user,$this->password);
if (!$this->conn){
die("数据库链接出问题啦".mysql_error());
}
mysql_select_db($this->db,$this->conn);
}
//完成select
public function execute_dql($sql){
$res=mysql_query($sql) or die (mysql_error());
return $res;

}
public function execute_dml($sql){
$b=mysql_query($sql,$this->conn);
if (!$b){
return 0;//失败
}else {
if (mysql_affected_rows($this->conn)>0){
return 1;//表示真的成功
}else {
return 2;//表示没有行数影响
}
}
}
}

<?php
//演示对user1表进行增删改操作
//删：    $sql="delete from user1 where id=数";
//更新：$sql="updata user1 set age=100 where id = 数值"；
/*  $conn=mysql_connect("localhost","root","root1142495240");
if (!$conn){
die("链接数据库出错la".mysql_error());
}
mysql_select_db("123",$conn);
mysql_query("set names utf8");
$sql="insert into user1 (name,password,age) values('小明','1111','55')";

$res=mysql_query( $sql,$conn);
if (!$res){
echo "操作失败".mysql_error();
}else {
echo "操作成功";
}
mysql_close($conn);

*/
/*****************dml操作**************/
require_once 'SQLtool_class.php';
$sql="insert into user1 (name,password,age) values('小明','1111','55')";
$sqltool=new SQLtool();
$res=$sqltool->execute_dml($sql);
if ($res==0){
echo "失败";
}else if ($res==1){
echo "成功";
}else if ($res==2){
echo "没有行数影响";
}

/*****************dql操作**************/
$sql="select * from user1";
$res=$sqltool->execute_dql($sql);
while ($row=mysql_fetch_row($res)){
foreach ($row as $key=>$val){
echo "--$val";
}
echo "<br>";
}

mysql_free_result($res);