php中PDO方式实现数据库的增删改查

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

    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() . '<br/>');
        }
      }
    }

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
      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

    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, $preType = array(PDO::ATTR_CURSOR => PDO::CURSOR_FWDONLY)) {
        if ($sql) {
          $sql .= ' limit ' . (int) $limit[0] . ',' . (intval($limit[1]) > 0 ? intval($limit[1]) : 10);
          $pdoStatement = $this->pdo->prepare($sql, $preType);
          $pdoStatement->execute($searchData);
          return $data = $pdoStatement->fetchAll($dataMode);
        } else {
          return false;
        }
      }

      public function insert($tableName, $data, $returnInsertId = false, $replace = false) {
        if(!empty($tableName) && count($data) > 0){
          $sql = $replace ? 'REPLACE INTO ' : 'INSERT INTO ';
          list($setSql, $mapData) = $this->FDFields($data);
          $sql .= $tableName . ' set ' . $setSql;
          $pdoStatement = $this->pdo->prepare($sql, array(PDO::ATTR_CURSOR => PDO::CURSOR_FWDONLY));
          $execRet = $pdoStatement->execute($mapData);
          return $execRet ? ($returnInsertId ? $this->pdo->lastInsertId() : $execRet) : false;
        } else {
          return false;
        }
      }

      public function update($tableName, $data, $condition, $mapData = array(), $returnRowCount = true) {
        if(!empty($tableName) && count($data) > 0) {
          $sql = 'UPDATE ' . $tableName . ' SET ';
          list($setSql, $mapSetData) = $this->FDFields($data);
          $sql .= $setSql;
          $mapData = array_merge($mapData, $mapSetData);
          list($where, $mapData) = $this->FDCondition($condition, $mapData);
          $sql .= $where ? ' WHERE ' . $where : '';
          $pdoStatement = $this->pdo->prepare($sql, array(PDO::ATTR_CURSOR => PDO::CURSOR_FWDONLY));
          $execRet = $pdoStatement->execute($mapData);
          return $execRet ? ($returnRowCount ? $pdoStatement->rowCount() : $execRet) : false;
        } else {
          return false;
        }
      }

      public function delete($tableName, $condition, $mapData = array()) {
        if(!empty($tableName) && $condition){
          $sql = 'DELETE FROM ' . $tableName;
          list($where, $mapData) = $this->FDCondition($condition, $mapData);
          $sql .= $where ? ' WHERE ' . $where : '';
          $pdoStatement = $this->pdo->prepare($sql, array(PDO::ATTR_CURSOR => PDO::CURSOR_FWDONLY));
          $execRet = $pdoStatement->execute($mapData);
          return $execRet;
        }
      }

测试文件test.php

    header("Content-type: text/html; charset=utf-8");
    define('APP_DIR', dirname(__FILE__));

    if (function_exists('spl_autoload_register')) {
      spl_autoload_register('autoClass');
    } else {
      function __auto_load($className){
        autoClass($className);
      }
    }

    function autoClass($className){
      try{
        require_once APP_DIR.'/class/'.$className.'.php';
      } catch (Exception $e) {
        die('Error:' . $e->getMessage() . '<br />');
      }
    }
    $DB = new DB();
    //插入
    $inData['a'] = rand(1, 100);
    $inData['b'] = rand(1, 1000);
    $inData['c'] = rand(1,200) . '.' . rand(1,100);
    $ret = $DB->insert('a', $inData);
    echo '插入' . ($ret ? '成功' : '失败') . '<br/>';
    //更新
    $upConData['a'] = 100;
    $upConJudge['a'] = '<';
    $upConData['b'] = 30;
    $upConJudge['b'] = '>';
    list($upConStr, $mapUpConData) = $DB->FDField('b', 200, '<', 'gt');
    $condition = array(
      'str' => $upConStr,
      'data' => $upConData,
      'judge' => $upConJudge,
      'link' => 'and'
    );
    $upData['a'] = rand(1, 10);
    $upData['b'] = 1;
    $upData['c'] = 1.00;
    $changeRows = $DB->update('a', $upData, $condition, $mapUpConData);
    echo '更新行数:' . (int) $changeRows . '<br/>';
    //删除
    $delVal = rand(1, 10);
    list($delCon, $mapDelCon) = $DB->FDField('a', $delVal);
    $delRet = $DB->delete('a', $delCon, $mapDelCon);
    echo '删除a=' . $delVal . ($delRet ? '成功' : '失败') . '<br/>';

    //查询
    $data['a'] = '10';
    $judge['a'] = '>';
    $data['b'] = '400';
    $judge['b'] = '<';
    list($conSql, $mapConData) = $DB->FDFields($data, 'and', $judge);
    $mData = $DB->fetch('select * from a where ' . $conSql . ' order by `a` desc', $mapConData);

    var_dump($mData);

以上所述就是本文的全部内容了，希望大家能够喜欢。