发布于 2016-04-23 13:58:57 | 163 次阅读 | 评论: 0 | 来源: 网友投递
PDO PHP 数据对象
POD是PHP一个扩展,PDO扩展为PHP访问数据库定义了一个轻量级的、一致性的接口，它提供了一个数据访问抽象层，这样，无论使用什么数据库，都可以通过一致的函数执行查询和获取数据。
这篇文章主要介绍了PHP的PDO常用类库,结合实例形式分析了PDO类库常见的连接,初始化及增删改查等操作技巧,需要的朋友可以参考下
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;
}
}