PHP的PDO常用类库实例分析

本文实例讲述了PHP的PDO常用类库。分享给大家供大家参考，具体如下：

1、Db.class.php 连接数据库

    <?php
    // 连接数据库
    class Db {
      static public function getDB() {
        try {
          $pdo = new PDO(DB_DSN, DB_USER, DB_PWD);
          $pdo->setAttribute(PDO::ATTR_PERSISTENT, true); // 设置数据库连接为持久连接
          $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); // 设置抛出错误
          $pdo->setAttribute(PDO::ATTR_ORACLE_NULLS, true); // 设置当字符串为空转换为 SQL 的 NULL
          $pdo->query('SET NAMES utf8'); // 设置数据库编码
        } catch (PDOException $e) {
          exit('数据库连接错误，错误信息：'. $e->getMessage());
        }
        return $pdo;
      }
    }
    ?>

2、Model.class.php 数据库操作类

    <?php
    /**
    * 数据库操作类库
    * author Lee.
    * Last modify $Date: 2012-1-19 13:59；04 $
    */
    class M {
      private $_db; //数据库句柄
      public $_sql; //SQL语句
      /**
       * 构造方法
       */
      public function __construct() {
        $this->_db = Db::getDB();
      }
      /**
       * 数据库添加操作
       * @param string $tName 表名
       * @param array $field 字段数组
       * @param array $val 值数组
       * @param bool $is_lastInsertId 是否返回添加ID
       * @return int 默认返回成功与否，$is_lastInsertId 为true，返回添加ID
       */
      public function insert($tName, $fields, $vals, $is_lastInsertId=FALSE) {
        try {
          if (!is_array($fields) || !is_array($vals))
            exit($this->getError(__FUNCTION__, __LINE__));
          $fields = $this->formatArr($fields);
          $vals = $this->formatArr($vals, false);
          $tName = $this->formatTabName($tName);
          $this->_sql = "INSERT INTO {$tName} ({$fields}) VALUES ({$vals})";
          if (!$is_lastInsertId) {
            $row = $this->_db->exec($this->_sql);
            return $row;
          } else {
            $this->_db->exec($this->_sql);
            $lastId = (int)$this->_db->lastInsertId();
            return $lastId;
          }
        } catch (PDOException $e) {
          exit($e->getMessage());
        }
      }
      /**
       * 数据库修改操作
       * @param string $tName 表名
       * @param array $field 字段数组
       * @param array $val 值数组
       * @param string $condition 条件
       * @return int 受影响的行数
       */
      public function update($tName, $fieldVal, $condition) {
        try {
          if (!is_array($fieldVal) || !is_string($tName) || !is_string($condition))
            exit($this->getError(__FUNCTION__, __LINE__));
          $tName = $this->formatTabName($tName);
          $upStr = '';
          foreach ($fieldVal as $k=>$v) {
            $upStr .= '`'.$k . '`=' . '\'' . $v . '\'' . ',';
          }
          $upStr = rtrim($upStr, ',');
          $this->_sql = "UPDATE {$tName} SET {$upStr} WHERE {$condition}";
          $row = $this->_db->exec($this->_sql);
          return $row;
        } catch (PDOException $e) {
          exit($e->getMessage());
        }
      }
      /**
       * 数据库删除操作（注：必须添加 where 条件）
       * @param string $tName 表名
       * @param string $condition 条件
       * @return int 受影响的行数
       */
      public function del($tName, $condition) {
        try {
          if (!is_string($tName) || !is_string($condition))
            exit($this->getError(__FUNCTION__, __LINE__));
          $tName= $this->formatTabName($tName);
          $this->_sql = "DELETE FROM {$tName} WHERE {$condition}";
          $row = $this->_db->exec($this->_sql);
          return $row;
        } catch (PDOException $e) {
          exit($e->getMessage());
        }
      }
      /**
       * 返回表总个数
       * @param string $tName 表名
       * @param string $condition 条件
       * @return int
       */
      public function total($tName, $condition='') {
        try {
          if (!is_string($tName))
            exit($this->getError(__FUNCTION__, __LINE__));
          $tName = $this->formatTabName($tName);
          $this->_sql = "SELECT COUNT(*) AS total FROM {$tName}" .
          ($condition=='' ? '' : ' WHERE ' . $condition);
          $re = $this->_db->query($this->_sql);
          foreach ($re as $v) {
            $total = $v['total'];
          }
          return (int)$total;
        } catch (PDOException $e) {
          exit($e->getMessage());
        }
      }
      /**
       * 数据库删除多条数据
       * @param string $tName 表名
       * @param string $field 依赖字段
       * @param array $ids 删除数组
       * @return int 受影响的行数
       */
      public function delMulti($tName, $field, $ids) {
        try {
          if (!is_string($tName) || !is_array($ids))
            exit($this->getError(__FUNCTION__, __LINE__));
          $delStr = '';
          $tName = $this->formatTabName($tName);
          $field = $this->formatTabName($field);
          foreach ($ids as $v) {
            $delStr .= $v . ',';
          }
          $delStr = rtrim($delStr, ',');
          $this->_sql = "DELETE FROM {$tName} WHERE {$field} IN ({$delStr})";
          $row = $this->_db->exec($this->_sql);
          return $row;
        } catch (PDOException $e) {
          exit($e->getMessage());
        }
      }
      /**
       * 获取表格的最后主键（注：针对 INT 类型）
       * @param string $tName 表名
       * @return int
       */
      public function insertId($tName) {
        try {
          if (!is_string($tName))
            exit($this->getError(__FUNCTION__, __LINE__));
          $this->_sql = "SHOW TABLE STATUS LIKE '{$tName}'";
          $result = $this->_db->query($this->_sql);
          $insert_id = 0;
          foreach ($result as $v) {
            $insert_id = $v['Auto_increment'];
          }
          return (int)$insert_id;
        } catch (PDOException $e) {
          exit($e->getMessage());
        }
      }
      /**
       * 检查数据是否已经存在（依赖条件）
       * @param string $tName 表名
       * @param string $field 依赖的字段
       * @return bool
       */
      public function exists($tName, $condition) {
        try {
          if (!is_string($tName) || !is_string($condition))
            exit($this->getError(__FUNCTION__, __LINE__));
          $tName = $this->formatTabName($tName);
          $this->_sql = "SELECT COUNT(*) AS total FROM {$tName} WHERE {$condition}";
          $result = $this->_db->query($this->_sql);
          foreach ($result as $v) {
             $b = $v['total'];
          }
          if ($b) {
            return true;
          } else {
            return false;
          }
        } catch (PDOException $e) {
          exit($e->getMessage());
        }
      }
      /**
       * 检查数据是否已经存在（依赖 INT 主键）
       * @param string $tName 表名
       * @param string $primary 主键
       * @param int $id 主键值
       * @return bool
       */
      public function existsByPK($tName, $primary, $id) {
        try {
          if (!is_string($tName) || !is_string($primary)
          || !is_int($id))
            exit($this->getError(__FUNCTION__, __LINE__));
          $tName = $this->formatTabName($tName);
          $this->_sql = "SELECT COUNT(*) AS total FROM {$tName} WHERE {$primary} = ". $id;
          $result = $this->_db->query($this->_sql);
          foreach ($result as $v) {
             $b = $v['total'];
          }
          if ($b) {
            return true;
          } else {
            return false;
          }
        } catch (PDOException $e) {
          exit($e->getMessage());
        }
      }
      /**
       * 预处理删除（注：针对主键为 INT 类型，推荐使用）
       * @param string $tName 表名
       * @param string $primary 主键字段
       * @param int or array or string $ids 如果是删除一条为 INT，多条为 array，删除一个范围为 string
       * @return int 返回受影响的行数
       */
      public function delByPK($tName, $primary, $ids, $mult=FALSE) {
        try {
          if (!is_string($tName) || !is_string($primary)
          || (!is_int($ids) && !is_array($ids) && !is_string($ids))
          || !is_bool($mult)) exit($this->getError(__FUNCTION__, __LINE__));
          $tName = $this->formatTabName($tName);
          $stmt = $this->_db->prepare("DELETE FROM {$tName} WHERE {$primary}=?");
          if (!$mult) {
            $stmt->bindParam(1, $ids);
            $row = $stmt->execute();
          } else {
            if (is_array($ids)) {
              $row = 0;
              foreach ($ids as $v) {
                $stmt->bindParam(1, $v);
                if ($stmt->execute()) {
                  $row++;
                }
              }
            } elseif (is_string($ids)) {
              if (!strpos($ids, '-'))
                exit($this->getError(__FUNCTION__, __LINE__));
              $split = explode('-', $ids);
              if (count($split)!=2 || $split[0]>$split[1])
                exit($this->getError(__FUNCTION__, __LINE__));
              $i = null;
              $count = $split[1]-$split[0]+1;
              for ($i=0; $i<$count; $i++) {
                $idArr[$i] = $split[0]++;
              }
              $idStr = '';
              foreach ($idArr as $id) {
                $idStr .= $id . ',';
              }
              $idStr = rtrim($idStr, ',');
              $this->_sql ="DELETE FROM {$tName} WHERE {$primary} in ({$idStr})";
              $row = $this->_db->exec($this->_sql);
            }
          }
          return $row;
        } catch (PDOException $e) {
          exit($e->getMessage());
        }
      }
      /**
       * 返回单个字段数据或单条记录
       * @param string $tName 表名
       * @param string $condition 条件
       * @param string or array $fields 返回的字段，默认是*
       * @return string || array
       */
      public function getRow($tName, $condition='', $fields="*") {
        try {
          if (!is_string($tName) || !is_string($condition)
          || !is_string($fields) || empty($fields))
             exit($this->getError(__FUNCTION__, __LINE__));
          $tName = $this->formatTabName($tName);
          $this->_sql = "SELECT {$fields} FROM {$tName} ";
          $this->_sql .= ($condition=='' ? '' : "WHERE {$condition}") . " LIMIT 1";
          $sth = $this->_db->prepare($this->_sql);
          $sth->execute();
          $result = $sth->fetch(PDO::FETCH_ASSOC);
          if ($fields === '*') {
            return $result;
          } else {
            return $result[$fields];
          }
        } catch (PDOException $e) {
          exit($e->getMessage());
        }
      }
      /**
       * 返回多条数据
       * @param string $tName 表名
       * @param string $fields 返回字段，默认为*
       * @param string $condition 条件
       * @param string $order 排序
       * @param string $limit 显示个数
       * @return PDOStatement
       */
      public function getAll($tName, $fields='*', $condition='', $order='', $limit='') {
        try {
          if (!is_string($tName) || !is_string($fields)
          || !is_string($condition) || !is_string($order)
          || !is_string($limit))
            exit($this->getError(__FUNCTION__, __LINE__));
          $tName = $this->formatTabName($tName);
          $fields = ($fields=='*' || $fields=='') ? '*' : $fields;
          $condition = $condition=='' ? '' : " WHERE ". $condition ;
          $order = $order=='' ? '' : " ORDER BY ". $order;
          $limit = $limit=='' ? '' : " LIMIT ". $limit;
          $this->_sql = "SELECT {$fields} FROM {$tName} {$condition} {$order} {$limit}";
          $sth = $this->_db->prepare($this->_sql);
          $sth->execute();
          $result = $sth->fetchAll(PDO::FETCH_ASSOC);
          return $result;
        } catch (PDOException $e) {
          exit($e->getMessage());
        }
      }
      /**
       * 格式化数组（表结构和值）
       * @param array $field
       * @param bool $isField
       * @return string
       */
      private function formatArr($field, $isField=TRUE) {
        if (!is_array($field)) exit($this->getError(__FUNCTION__, __LINE__));
        $fields = '';
        if ($isField) {
          foreach ($field as $v) {
            $fields .= '`'.$v.'`,';
          }
        } else {
          foreach ($field as $v) {
            $fields .= '\''.$v.'\''.',';
          }
        }
        $fields = rtrim($fields, ',');
        return $fields;
      }
      /**
       * 格式化问号
       * @param int $count 数量
       * @return string 返回格式化后的字符串
       */
      private function formatMark($count) {
        $str = '';
        if (!is_int($count)) exit($this->getError(__FUNCTION__, __LINE__));
        if ($count==1) return '?';
        for ($i=0; $i<$count; $i++) {
          $str .= '?,';
        }
        return rtrim($str, ',');
      }
      /**
       * 错误提示
       * @param string $fun
       * @return string
       */
      private function getError($fun, $line) {
        return __CLASS__ . '->' . $fun . '() line<font color="red">'. $line .'</font> ERROR!';
      }
      /**
       * 处理表名
       * @param string $tName
       * @return string
       */
      private function formatTabName($tName) {
        return '`' . trim($tName, '`') . '`';
      }
      /**
       * 析构方法
       */
      public function __destruct() {
        $this->_db = null;
      }
    }

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