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php中PDO方式实现数据库的增删改查

　　PDO是mysql数据库操作的一个公用类了，我们不需要进行自定类就可以直接使用pdo来操作数据库了，但是在php默认配置中pdo是未开启所以我们必须先在php.ini中开启它才可以使用。

　　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() . '
');

}

　　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() . '
');

}

$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') . '
';

//更新

$upConData['a'] = 100;

$upConJudge['a'] = '

$upConData['b'] = 30;

$upConJudge['b'] = '>';

list($upConStr, $mapUpConData) = $DB->FDField('b', 200, '

$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 . '
';

//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') . '
';

//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。