实用mysql数据库连接类

这是一款php中的mysql数据库连接文件代码，如果你正在找这样功能的代码，可以进来看看，非常完整文件

这是一款php教程中的mysql教程数据库教程连接文件代码，如果你正在找这样功能的代码，可以进来看看，非常完整文件。*/

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;
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) $this->show_error("sql语句 "$sql" 执行时遇到错误");
return $this->query_id;
}

// 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
";
$i = 1;
while ($row = $this->fetch_array($this->query_id)){
echo "$i -- $row[0]
";
$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
";
$i = 1;
while ($this->row = $this->fetch_array($this->query_id)){
echo "$i -- ".$this->row[database]."
";
$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();
}

// 显示错误信息
public function show_error ($msg) {
$errinfo = mysql_error();
echo "错误：$msg
返回：$errinfo

";
}

// 释放内存
public function free_result () {
if ( @mysql_free_result($this->query_id) )
unset ($this->result);
$this->query_id = 0;
}

} // end class