Question

php封装一个class类实现mysql数据库的增删该查

封装一个mysql类，能实现数据库的增删改查
public function select($res = null){
if(is_resource($res) && !is_null($res)){
$this->res = $res; } $data =array();
while($list=@mysql_fetch_assoc($this->res)){
$data[]=$list;
} print_r($data);

return $data; } /* find() $can :结果集 */ public function find($res = null){
if(is_resource($res) && !is_null($res)){
$this->res = $res; } return @mysql_fetch_assoc($this->res); }

Answer 1

<?php
class db{
private $db;
const MYSQL_OPT_READ_TIMEOUT = 11;
const MYSQL_OPT_WRITE_TIMEOUT = 12;
private $tbl_name;
private $where;
private $sort;
private $fields;
private $limit;
public static $_instance = null;
function __construct(){
$cfg = loadConfig('db');
$db = mysqli_init();
$db->options(self::MYSQL_OPT_READ_TIMEOUT, 3);
$db->options(self::MYSQL_OPT_WRITE_TIMEOUT, 1);
@$db->real_connect($cfg['host'],$cfg['user'],$cfg['pwd'],$cfg['db']);
if ($db->connect_error) {
$this->crash($db->errno,$db->error);
}
$db->set_charset("utf8");
$this->db = $db;
//echo $this->db->stat;
}
public static function getInstance(){
if(!(self::$_instance instanceof self)){
self::$_instance = new self();
}
return self::$_instance;
}
private function __clone() {} //覆盖__clone()方法，禁止克隆
public function find($conditions = null){
if($conditions) $this->where($conditions);
return $this->getArray($this->buildSql(),1);
}
public function findAll($conditions = null){
if($conditions) $this->where($conditions);
return $this->getArray($this->buildSql());
}
//表
public function t($table){ $this->tbl_name = $table; return $this;}
//条件
public function where($conditions){
$where = '';
if(is_array($conditions)){
$join = array();
foreach( $conditions as $key => $condition ){
$condition = $this->db->real_escape_string($condition);
$join[] = "`{$key}` = '{$condition}'";
}
$where = "WHERE ".join(" AND ",$join);
}else{
if(null != $conditions) $where = "WHERE ".$conditions;
}
$this->where = $where;
return $this;
}
//排序
public function sort($sort){
if(null != $sort) $sort = "ORDER BY {$sort}";
$this->sort = $sort;
return $this;
}
//字段
public function fields($fields){ $this->fields = $fields; return $this; }
public function limit($limit){$this->limit = $limit; return $this;}
private function buildSql(){
$this->fields = empty($this->fields) ? "*" : $this->fields;
$sql = "SELECT {$this->fields} FROM {$this->tbl_name} {$this->where} {$this->sort}";
accessLog('db_access',$sql);
if(null != $this->limit)$sql .= " limit {$this->limit}";
return $sql;
}
/**
* 返回查询数据
* @param $sql
* @param bool $hasOne
* @return array|bool|mixed
*/
private function getArray($sql,$hasOne = false){
if($this->db->real_query($sql) ){
if ($result = $this->db->use_result()) {
$row = array();
if($hasOne){
$row = $result->fetch_assoc();
}else{
while($d = $result->fetch_assoc()) $row[] = $d;
}
$result->close();
$this->fields = "*";
return $row;
}else{
return false;
}
}else{
if($this->db->error){
$this->crash($this->db->errno,$this->db->error,$sql);
}
}
}
public function findSql($sql,$hasOne = false){
accessLog('db_access',$sql);
if($this->db->real_query($sql) ){
if ($result = $this->db->use_result()) {
$row = array();
if($hasOne){
$row = $result->fetch_assoc();
}else{
while($d = $result->fetch_assoc()) $row[] = $d;
}
$result->close();
$this->fields = "*";
return $row;
}else{
return false;
}
}else{
if($this->db->error){
$this->crash($this->db->errno,$this->db->error,$sql);
}
}
}
public function create($row){
if(!is_array($row))return FALSE;
$row = $this->prepera_format($row);
if(empty($row))return FALSE;
foreach($row as $key => $value){
$cols[] = '`'.$key.'`';
$vals[] = "'".$this->db->real_escape_string($value)."'";
}
$col = implode(',', $cols);
$val = implode(',', $vals);
$sql = "INSERT INTO `{$this->tbl_name}` ({$col}) VALUES ({$val})";
accessLog('db_access',$sql);
if( FALSE != $this->db->query($sql) ){ // 获取当前新增的ID
if($this->db->insert_id){
return $this->db->insert_id;
}
if($this->db->affected_rows){
return true;
}
}
return FALSE;
}
//直接执行sql
public function runSql($sql){
accessLog('db_access',$sql);
if( FALSE != $this->db->query($sql) ){ // 获取当前新增的ID
return true;
}else{
return false;
}
}
public function update($row){
$where = "";
$row = $this->prepera_format($row);
if(empty($row))return FALSE;
foreach($row as $key => $value){
$value = $this->db->real_escape_string($value);
$vals[] = "`{$key}` = '{$value}'";
}
$values = join(", ",$vals);
$sql = "UPDATE {$this->tbl_name} SET {$values} {$this->where}";
accessLog('db_access',$sql);
if( FALSE != $this->db->query($sql) ){ // 获取当前新增的ID
if( $this->db->affected_rows){
return true;
}
}
return false;
}
function delete(){
$sql = "DELETE FROM {$this->tbl_name} {$this->where}";
if( FALSE != $this->db->query($sql) ){ // 获取当前新增的ID
if( $this->db->affected_rows){
return true;
}
}
return FALSE;
}
private function prepera_format($rows){
$columns = $this->getArray("DESCRIBE {$this->tbl_name}");
$newcol = array();
foreach( $columns as $col ){
$newcol[$col['Field']] = $col['Field'];
}
return array_intersect_key($rows,$newcol);
}
//崩溃信息
private function crash($number,$message,$sql=''){
$msg = 'Db Error '.$number.':'.$message ;
if(empty($sql)){
echo t('db_crash');
}else{
$msg .= " SQL:".$sql;
echo t('db_query_err');
}
accessLog('db_error',$msg);
exit;
}
}

Answer 2

class db_mysql
{
var $querynum = 0 ; //当前页面进程查询数据库的次数
var $dblink ; //数据库连接资源

//链接数据库
function connect($dbhost,$dbuser,$dbpw,$dbname='',$dbcharset='utf-8',$pconnect=0 , $halt=true)
{
$func = empty($pconnect) ? 'mysql_connect' : 'mysql_pconnect' ;
$this->dblink = @$func($dbhost,$dbuser,$dbpw) ;
if ($halt && !$this->dblink)
{
$this->halt("无法链接数据库！");
}

//设置查询字符集
mysql_query("SET character_set_connection={$dbcharset},character_set_results={$dbcharset},character_set_client=binary",$this->dblink) ;

//选择数据库
$dbname && @mysql_select_db($dbname,$this->dblink) ;
}

//选择数据库
function select_db($dbname)
{
return mysql_select_db($dbname,$this->dblink);
}

//执行SQL查询
function query($sql)
{
$this->querynum++ ;
return mysql_query($sql,$this->dblink) ;
}

//返回最近一次与连接句柄关联的INSERT，UPDATE 或DELETE 查询所影响的记录行数
function affected_rows()
{
return mysql_affected_rows($this->dblink) ;
}

//取得结果集中行的数目,只对select查询的结果集有效
function num_rows($result)
{
return mysql_num_rows($result) ;
}

//获得单格的查询结果
function result($result,$row=0)
{
return mysql_result($result,$row) ;
}

//取得上一步 INSERT 操作产生的 ID,只对表有AUTO_INCREMENT ID的操作有效
function insert_id()
{
return ($id = mysql_insert_id($this->dblink)) >= 0 ? $id : $this->result($this->query("SELECT last_insert_id()"), 0);
}

//从结果集提取当前行，以数字为key表示的关联数组形式返回
function fetch_row($result)
{
return mysql_fetch_row($result) ;
}

//从结果集提取当前行，以字段名为key表示的关联数组形式返回
function fetch_assoc($result)
{
return mysql_fetch_assoc($result);
}

//从结果集提取当前行，以字段名和数字为key表示的关联数组形式返回
function fetch_array($result)
{
return mysql_fetch_array($result);
}

//关闭链接
function close()
{
return mysql_close($this->dblink) ;
}

//输出简单的错误html提示信息并终止程序
function halt($msg)
{
$message = "<html>\n<head>\n" ;
$message .= "<meta content='text/html;charset=gb2312'>\n" ;
$message .= "</head>\n" ;
$message .= "<body>\n" ;
$message .= "数据库出错：".htmlspecialchars($msg)."\n" ;
$message .= "</body>\n" ;
$message .= "</html>" ;

echo $message ;
exit ;
}
}

Answer 3

class sqlHelper{
public $conn;
public $dbname="数据库名称";
public $username="数据库用户名";
public $password="数据库密码";
public $host="localhost";
//连接数据库
public function __construct(){
$this->conn=mysql_connect($this->host,$this->username,$this->password);
if(!$this->conn){
die("连接失败".mysql_error());
}
mysql_select_db($this->dbname,$this->conn);
}
//执行查询语句
public function execute_dql($sql){
$res=mysql_query($sql,$this->conn);
return $res;
}
//执行增填改语句
public function execute_dml($sql){
$b=mysql_query($sql,$this->conn);
if(!$b){
return 3;
}else{
if(mysql_affected_rows($this->conn)){
return 1;//表示OK
}else{
return 2;//表示没有行收到影响
}
}
}
}