_host = $conf['host'];
$this->_port = $conf['port'];
$this->_user = $conf['user'];
$this->_pass = $conf['passwd'];
$this->_dbName = $conf['dbname'];
//连接数据库
if ( is_null(self::$_dbh) ) {
$this->_connect();
}
}
/**
* 连接数据库的方法
*/
protected function _connect() {
$dsn = $this->_dbType.':host='.$this->_host.';port='.$this->_port.';dbname='.$this->_dbName;
$options = $this->_pconnect ? array(PDO::ATTR_PERSISTENT=>true) : array();
try {
$dbh = new PDO($dsn, $this->_user, $this->_pass, $options);
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); //设置如果sql语句执行错误则抛出异常，事务会自动回滚
$dbh->setAttribute(PDO::ATTR_EMULATE_PREPARES, false); //禁用prepared statements的仿真效果(防SQL注入)
} catch (PDOException $e) {
die('Connection failed: ' . $e->getMessage());
}
$dbh->exec('SET NAMES utf8');
self::$_dbh = $dbh;
}
/**
* 字段和表名添加 `符号
* 保证指令中使用关键字不出错 针对mysql
* @param string $value
* @return string
*/
protected function _addChar($value) {
if ('*'==$value || false!==strpos($value,'(') || false!==strpos($value,'.') || false!==strpos($value,'`')) {
//如果包含* 或者 使用了sql方法 则不作处理
} elseif (false === strpos($value,'`') ) {
$value = '`'.trim($value).'`';
}
return $value;
}
/**
* 取得数据表的字段信息
* @param string $tbName 表名
* @return array
*/
protected function _tbFields($tbName) {
$sql = 'SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME="'.$tbName.'" AND TABLE_SCHEMA="'.$this->_dbName.'"';
$stmt = self::$_dbh->prepare($sql);
$stmt->execute();
$result = $stmt->fetchAll(PDO::FETCH_ASSOC);
$ret = array();
foreach ($result as $key=>$value) {
$ret[$value['COLUMN_NAME']] = 1;
}
return $ret;
}
/**
* 过滤并格式化数据表字段
* @param string $tbName 数据表名
* @param array $data POST提交数据
* @return array $newdata
*/
protected function _dataFormat($tbName,$data) {
if (!is_array($data)) return array();
$table_column = $this->_tbFields($tbName);
$ret=array();
foreach ($data as $key=>$val) {
if (!is_scalar($val)) continue; //值不是标量则跳过
if (array_key_exists($key,$table_column)) {
$key = $this->_addChar($key);
if (is_int($val)) {
$val = intval($val);
} elseif (is_float($val)) {
$val = floatval($val);
} elseif (preg_match('/^\(\w*(\+|\-|\*|\/)?\w*\)$/i', $val)) {
// 支持在字段的值里面直接使用其它字段 ,例如 (score+1) (name) 必须包含括号
$val = $val;
} elseif (is_string($val)) {
$val = '"'.addslashes($val).'"';
}
$ret[$key] = $val;
}
}
return $ret;
}
/**
* 执行查询 主要针对 SELECT, SHOW 等指令
* @param string $sql sql指令
* @return mixed
*/
protected function _doQuery($sql='') {
$this->_sql = $sql;
$pdostmt = self::$_dbh->prepare($this->_sql); //prepare或者query 返回一个PDOStatement
$pdostmt->execute();
$result = $pdostmt->fetchAll(PDO::FETCH_ASSOC);
return $result;
}
/**
* 执行语句 针对 INSERT, UPDATE 以及DELETE,exec结果返回受影响的行数
* @param string $sql sql指令
* @return integer
*/
protected function _doExec($sql='') {
$this->_sql = $sql;
return self::$_dbh->exec($this->_sql);
}
/**
* 执行sql语句，自动判断进行查询或者执行操作
* @param string $sql SQL指令
* @return mixed
*/
public function doSql($sql='') {
$queryIps = 'INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|LOAD DATA|SELECT .* INTO|COPY|ALTER|GRANT|REVOKE|LOCK|UNLOCK';
if (preg_match('/^\s*"?(' . $queryIps . ')\s+/i', $sql)) {
return $this->_doExec($sql);
}
else {
//查询操作
return $this->_doQuery($sql);
}
}
/**
* 获取最近一次查询的sql语句
* @return String 执行的SQL
*/
public function getLastSql() {
return $this->_sql;
}
/**
* 插入方法
* @param string $tbName 操作的数据表名
* @param array $data 字段-值的一维数组
* @return int 受影响的行数
*/
public function insert($tbName,array $data){
$data = $this->_dataFormat($tbName,$data);
if (!$data) return;
$sql = "insert into ".$tbName."(".implode(',',array_keys($data)).") values(".implode(',',array_values($data)).")";
return $this->_doExec($sql);
}
/**
* 删除方法
* @param string $tbName 操作的数据表名
* @return int 受影响的行数
*/
public function delete($tbName) {
//安全考虑,阻止全表删除
if (!trim($this->_where)) return false;
$sql = "delete from ".$tbName." ".$this->_where;
$this->_clear = 1;
$this->_clear();
return $this->_doExec($sql);
}
/**
* 更新函数
* @param string $tbName 操作的数据表名
* @param array $data 参数数组
* @return int 受影响的行数
*/
public function update($tbName,array $data) {
//安全考虑,阻止全表更新
if (!trim($this->_where)) return false;
$data = $this->_dataFormat($tbName,$data);
if (!$data) return;
$valArr = '';
foreach($data as $k=>$v){
$valArr[] = $k.'='.$v;
}
$valStr = implode(',', $valArr);
$sql = "update ".trim($tbName)." set ".trim($valStr)." ".trim($this->_where);
return $this->_doExec($sql);
}
/**
* 查询函数
* @param string $tbName 操作的数据表名
* @return array 结果集
*/
public function select($tbName='') {
$sql = "select ".trim($this->_field)." from ".$tbName." ".trim($this->_where)." ".trim($this->_order)." ".trim($this->_limit);
$this->_clear = 1;
$this->_clear();
return $this->_doQuery(trim($sql));
}
/**
* @param mixed $option 组合条件的二维数组，例：$option['field1'] = array(1,'=>','or')
* @return $this
*/
public function where($option) {
if ($this->_clear>0) $this->_clear();
$this->_where = ' where ';
$logic = 'and';
if (is_string($option)) {
$this->_where .= $option;
}
elseif (is_array($option)) {
foreach($option as $k=>$v) {
if (is_array($v)) {
$relative = isset($v[1]) ? $v[1] : '=';
$logic = isset($v[2]) ? $v[2] : 'and';
$condition = ' ('.$this->_addChar($k).' '.$relative.' '.$v[0].') ';
}
else {
$logic = 'and';
$condition = ' ('.$this->_addChar($k).'='.$v.') ';
}
$this->_where .= isset($mark) ? $logic.$condition : $condition;
$mark = 1;
}
}
return $this;
}
/**
* 设置排序
* @param mixed $option 排序条件数组 例:array('sort'=>'desc')
* @return $this
*/
public function order($option) {
if ($this->_clear>0) $this->_clear();
$this->_order = ' order by ';
if (is_string($option)) {
$this->_order .= $option;
}
elseif (is_array($option)) {
foreach($option as $k=>$v){
$order = $this->_addChar($k).' '.$v;
$this->_order .= isset($mark) ? ','.$order : $order;
$mark = 1;
}
}
return $this;
}
/**
* 设置查询行数及页数
* @param int $page pageSize不为空时为页数，否则为行数
* @param int $pageSize 为空则函数设定取出行数，不为空则设定取出行数及页数
* @return $this
*/
public function limit($page,$pageSize=null) {
if ($this->_clear>0) $this->_clear();
if ($pageSize===null) {
$this->_limit = "limit ".$page;
}
else {
$pageval = intval( ($page - 1) * $pageSize);
$this->_limit = "limit ".$pageval.",".$pageSize;
}
return $this;
}
/**
* 设置查询字段
* @param mixed $field 字段数组
* @return $this
*/
public function field($field){
if ($this->_clear>0) $this->_clear();
if (is_string($field)) {
$field = explode(',', $field);
}
$nField = array_map(array($this,'_addChar'), $field);
$this->_field = implode(',', $nField);
return $this;
}
/**
* 清理标记函数
*/
protected function _clear() {
$this->_where = '';
$this->_order = '';
$this->_limit = '';
$this->_field = '*';
$this->_clear = 0;
}
/**
* 手动清理标记
* @return $this
*/
public function clearKey() {
$this->_clear();
return $this;
}
/**
* 启动事务
* @return void
*/
public function startTrans() {
//数据rollback 支持
if ($this->_trans==0) self::$_dbh->beginTransaction();
$this->_trans++;
return;
}
/**
* 用于非自动提交状态下面的查询提交
* @return boolen
*/
public function commit() {
$result = true;
if ($this->_trans>0) {
$result = self::$_dbh->commit();
$this->_trans = 0;
}
return $result;
}
/**
* 事务回滚
* @return boolen
*/
public function rollback() {
$result = true;
if ($this->_trans>0) {
$result = self::$_dbh->rollback();
$this->_trans = 0;
}
return $result;
}
/**
* 关闭连接
* PHP 在脚本结束时会自动关闭连接。
*/
public function close() {
if (!is_null(self::$_dbh)) self::$_dbh = null;
}
}
2. 例子
101,
'aa'=>123456,
'bbc'=>'aaaaaaaaaaaaaa',
);
$mysql->insert('t_table',$data);
//查询
$res = $mysql->field(array('sid','aa','bbc'))
->order(array('sid'=>'desc','aa'=>'asc'))
->where(array('sid'=>"101",'aa'=>array('123455','>','or')))
->limit(1,2)
->select('t_table');
$res = $mysql->field('sid,aa,bbc')
->order('sid desc,aa asc')
->where('sid=101 or aa>123455')
->limit(1,2)
->select('t_table');
//获取最后执行的sql语句
$sql = $mysql->getLastSql();
//直接执行sql语句
$sql = "show tables";
$res = $mysql->doSql($sql);
//事务
$mysql->startTrans();
$mysql->where(array('sid'=>102))->update('t_table',array('aa'=>666666));
$mysql->where(array('sid'=>103))->update('t_table',array('bbc'=>'呵呵8888呵呵'));
$mysql->where(array('sid'=>104))->delete('t_table');
$mysql->commit(); 
