代码如下:
<?php
class Mysql {
private $db_host; //主机地址
private $db_user; //用户名
private $db_pass; //连接密码
private $db_name; //名称
private $db_charset; //编码
private $conn;
public $debug=false;//调试开关，默认关闭
private $query_id; //用于判断sql语句是否执行成功
private $result; //结果集
private $num_rows; //结果集中行的数目，仅对select有效
private $insert_id; //上一步 INSERT 操作产生的 ID
// 构造/析构函数
function __construct ($db_host,$db_user,$db_pass,$db_name,$db_charset,$conn) {
$this->db_host = $db_host ;
$this->db_user = $db_user ;
$this->db_pass = $db_pass ;
$this->db_name = $db_name ;
$this->db_charset = $db_charset ;
$this->conn = $conn ;
$this->connect();
}
function __destruct () {
@mysql_close($this->conn);
}
// 连接/选择数据库
public function connect () {
if ($this->conn == 'pconn') {
@$this->conn = mysql_pconnect($this->db_host,$this->db_user,$this->db_pass);
} else {
@$this->conn = mysql_connect($this->db_host,$this->db_user,$this->db_pass);
}
if (!$this->conn) {
$this->show_error('数据库-连接失败：用户名或密码错误！');
}
if (!@mysql_select_db($this->db_name,$this->conn)) {
$this->show_error("数据库-选择失败：数据库 $this->db_name 不可用");
}
mysql_query("SET NAMES $this->db_charset");
return $this->conn;
}
// query方法
public function query ($sql) {
if ($this->query_id) $this->free_result();
$this->query_id = @mysql_query($sql,$this->conn);
if (!$this->query_id) $this->show_error("SQL语句 <b>\"$sql\"</b> 执行时遇到错误");
return $this->query_id;
}
// 显示详细错误信息
public function show_error ($msg) {
if($this->debug){
$errinfo = mysql_error();
echo "错误：$msg <br/> 返回：$errinfo<p>";
}else{
echo '<p>出现错误！<p>';
}
}
// 获得query执行成功与否的信息
public function get_query_info($info){
if ($this->query_id) {
echo $info;
}
}
// 查询所有
public function findall ($table_name) {
$this->query("select * from $table_name");
}
// mysql_fetch_array
public function fetch_array () {
if ($this->query_id) {
$this->result = mysql_fetch_array($this->query_id);
return $this->result;
}
}
// ......
public function fetch_assoc () {
if ($this->query_id) {
$this->result = mysql_fetch_assoc($this->query_id);
return $this->result;
}
}
public function fetch_row () {
if ($this->query_id) {
$this->result = mysql_fetch_row($this->query_id);
return $this->result;
}
}
public function fetch_object () {
if ($this->query_id) {
$this->result = mysql_fetch_object($this->query_id);
return $this->result;
}
}
// 获取 num_rows
public function num_rows () {
if ($this->query_id) {
$this->num_rows = mysql_num_rows($this->query_id);
return $this->num_rows;
}
}
// 获取 insert_id
public function insert_id () {
return $this->insert_id = mysql_insert_id();
}
// 显示共有多少张表
public function show_tables () {
$this->query("show tables");
if ($this->query_id) {
echo "数据库 $this->db_name 共有 ".$this->num_rows($this->query_id)." 张表<br/>";
$i = 1;
while ($row = $this->fetch_array($this->query_id)){
echo "$i -- $row[0]<br/>";
$i ++;
}
}
}
// 显示共有多少个数据库
public function show_dbs(){
$this->query("show databases");
if ($this->query_id) {
echo "共有数据库 ".$this->num_rows($this->query_id)." 个<br/>";
$i = 1;
while ($this->row = $this->fetch_array($this->query_id)){
echo "$i -- ".$this->row[Database]."<br />";
$i ++;
}
}
}
// 删除数据库：返回删除结果
public function drop_db ($db_name='') {
if ($db_name == '') {
$db_name = $this->db_name;//默认删除当前数据库
$this->query("DROP DATABASE $db_name");
}else {
$this->query("DROP DATABASE $db_name");
}
if ($this->query_id) {
return "数据库 $db_name 删除成功";
}else {
$this->show_error("数据库 $db_name 删除失败");
}
}
// 删除数据表：返回删除结果
public function drop_table ($table_name) {
$this->query("DROP TABLE $table_name");
if ($this->query_id) {
return "数据表 $table_name 删除成功";
}else {
$this->show_error("数据表 $table_name 删除失败");
}
}
// 创建数据库
public function create_db ($db_name) {
$this->query("CREATE DATABASE $db_name");
if($this->query_id){
return "数据库 $db_name 创建成功";
}else {
$this->show_error("数据库 $db_name 创建失败");
}
}
// 获取数据库版本
public function get_info(){
echo mysql_get_server_info();
}
// 释放内存
public function free_result () {
if ( @mysql_free_result($this->query_id) )
unset ($this->result);
$this->query_id = 0;
}
} // End class
?>