整理的比较容易理解的PDO操作实例，注意，需要开启php的pdo支持，php5.1以上版本支持实现
数据库连接单例化，有三要素 静态变量、静态实例化方法、私有构造函数 DPDO.php
//PDO操作类
//author http://www.lai18.com
class DPDO{
private $DSN;
private $DBUser;
private $DBPwd;
private $longLink;
private $pdo;
//私有构造函数 防止被直接实例化
private function __construct($dsn, $DBUser, $DBPwd, $longLink = false) {
$this->DSN = $dsn;
$this->DBUser = $DBUser;
$this->DBPwd = $DBPwd;
$this->longLink = $longLink;
$this->connect();
}
//私有 空克隆函数 防止被克隆
private function __clone(){}
//静态 实例化函数 返回一个pdo对象
static public function instance($dsn, $DBUser, $DBPwd, $longLink = false){
static $singleton = array();//静态函数 用于存储实例化对象
$singIndex = md5($dsn . $DBUser . $DBPwd . $longLink);
if (empty($singleton[$singIndex])) {
$singleton[$singIndex] = new self($dsn, $DBUser, $DBPwd, $longLink = false);
}
return $singleton[$singIndex]->pdo;
}
private function connect(){
try{
if($this->longLink){
$this->pdo = new PDO($this->DSN, $this->DBUser, $this->DBPwd, array(PDO::ATTR_PERSISTENT => true));
}else{
$this->pdo = new PDO($this->DSN, $this->DBUser, $this->DBPwd);
}
$this->pdo->query('SET NAMES UTF-8');
} catch(PDOException $e) {
die('Error:' . $e->getMessage() . '
');
}
}
}
用于处理字段映射，使用pdo的字段映射，可以有效避免sql注入
//字段关联数组处理， 主要用于写入和更新数据、同and 或 or 的查询条件，产生sql语句和映射字段的数组
//author http://www.lai18.com
public function FDFields($data, $link = ',', $judge = array(), $aliasTable = ''){
$sql = '';
$mapData = array();
foreach($data as $key => $value) {
$mapIndex = ':' . ($link != ',' ? 'c' : '') . $aliasTable . $key;
$sql .= ' ' . ($aliasTable ? $aliasTable . '.' : '') . '`' . $key . '` ' . ($judge[$key] ? $judge[$key] : '=') . ' ' . $mapIndex . ' ' . $link;
$mapData[$mapIndex] = $value;
}
$sql = trim($sql, $link);
return array($sql, $mapData);
}
//用于处理单个字段处理
public function FDField($field, $value, $judge = '=', $preMap = 'cn', $aliasTable = '') {
$mapIndex = ':' . $preMap . $aliasTable . $field;
$sql = ' ' . ($aliasTable ? $aliasTable . '.' : '') . '`' . $field . '`' . $judge . $mapIndex;
$mapData[$mapIndex] = $value;
return array($sql, $mapData);
}
//使用刚方法可以便捷产生查询条件及对应数据数组
public function FDCondition($condition, $mapData) {
if(is_string($condition)) {
$where = $condition;
} else if (is_array($condition)) {
if($condition['str']) {
if (is_string($condition['str'])) {
$where = $condition['str'];
} else {
return false;
}
}
if(is_array($condition['data'])) {
$link = $condition['link'] ? $condition['link'] : 'and';
list($conSql, $mapConData) = $this->FDFields($condition['data'], $link, $condition['judge']);
if ($conSql) {
$where .= ($where ? ' ' . $link : '') . $conSql;
$mapData = array_merge($mapData, $mapConData);
}
}
}
return array($where, $mapData);
}
增删改查的具体实现DB.php
//数据库的遍历
//author http://www.lai18.com
public function fetch($sql, $searchData = array(), $dataMode = PDO::FETCH_ASSOC, $preType = array(PDO::ATTR_CURSOR => PDO::CURSOR_FWDONLY)) {
if ($sql) {
$sql .= ' limit 1';
$pdoStatement = $this->pdo->prepare($sql, $preType);
$pdoStatement->execute($searchData);
return $data = $pdoStatement->fetch($dataMode);
} else {
return false;
}
}
public function fetchAll($sql, $searchData = array(), $limit = array(0, 10), $dataMode = PDO::FETCH_ASSOC, $preType = array(PDO::ATTR_CURSOR => PDO::CUR