<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2012 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

defined('THINK_PATH') or exit();
/**
 * MSsql数据库驱动 要求sqlserver2005
 * @category   Extend
 * @package  Extend
 * @subpackage  Driver.Db
 * @author    liu21st <liu21st@gmail.com>
 */
class DbMssql extends Db{
    protected $selectSql  =     'SELECT T1.* FROM (SELECT thinkphp.*, ROW_NUMBER() OVER (%ORDER%) AS ROW_NUMBER FROM (SELECT %DISTINCT% %FIELD% FROM %TABLE%%JOIN%%WHERE%%GROUP%%HAVING%) AS thinkphp) AS T1 %LIMIT%';
    /**
     * 架构函数 读取数据库配置信息
     * @access public
     * @param array $config 数据库配置数组
     */
    public function __construct($config=''){
        if ( !function_exists('mssql_connect') ) {
            throw_exception(L('_NOT_SUPPERT_').':mssql');
        }
        if(!empty($config)) {
            $this->config	=	$config;
            if(empty($this->config['params'])) {
                $this->config['params'] =   array();
            }
        }
    }

    /**
     * 连接数据库方法
     * @access public
     */
    public function connect($config='',$linkNum=0) {
        if ( !isset($this->linkID[$linkNum]) ) {
            if(empty($config))	$config  =  $this->config;
            $pconnect   = !empty($config['params']['persist'])? $config['params']['persist']:$this->pconnect;
            $conn = $pconnect ? 'mssql_pconnect':'mssql_connect';
            // 处理不带端口号的socket连接情况
            $sepr = IS_WIN ? ',' : ':';
            $host = $config['hostname'].($config['hostport']?$sepr."{$config['hostport']}":'');
            $this->linkID[$linkNum] = $conn( $host, $config['username'], $config['password']);
            if ( !$this->linkID[$linkNum] )  throw_exception("Couldn't connect to SQL Server on $host");
            if ( !empty($config['database'])  && !mssql_select_db($config['database'], $this->linkID[$linkNum]) ) {
                throw_exception("Couldn't open database '".$config['database']);
            }
            // 标记连接成功
            $this->connected =  true;
            //注销数据库安全信息
            if(1 != C('DB_DEPLOY_TYPE')) unset($this->config);
        }
        return $this->linkID[$linkNum];
    }

    /**
     * 释放查询结果
     * @access public
     */
    public function free() {
        mssql_free_result($this->queryID);
        $this->queryID = null;
    }

    /**
     * 执行查询  返回数据集
     * @access public
     * @param string $str  sql指令
     * @return mixed
     */
    public function query($str) {
        $this->initConnect(false);
        if ( !$this->_linkID ) return false;
        $this->queryStr = $str;
        //释放前次的查询结果
        if ( $this->queryID ) $this->free();
        N('db_query',1);
        // 记录开始执行时间
        G('queryStartTime');
        $this->queryID = mssql_query($str, $this->_linkID);
        $this->debug();
        if ( false === $this->queryID ) {
            $this->error();
            return false;
        } else {
            $this->numRows = mssql_num_rows($this->queryID);
            return $this->getAll();
        }
    }

    /**
     * 执行语句
     * @access public
     * @param string $str  sql指令
     * @return integer
     */
    public function execute($str) {
        $this->initConnect(true);
        if ( !$this->_linkID ) return false;
        $this->queryStr = $str;
        //释放前次的查询结果
        if ( $this->queryID ) $this->free();
        N('db_write',1);
        // 记录开始执行时间
        G('queryStartTime');
        $result	=	mssql_query($str, $this->_linkID);
        $this->debug();
        if ( false === $result ) {
            $this->error();
            return false;
        } else {
            $this->numRows = mssql_rows_affected($this->_linkID);
            $this->lastInsID = $this->mssql_insert_id();
            return $this->numRows;
        }
    }

    /**
     * 用于获取最后插入的ID
     * @access public
     * @return integer
     */
    public function mssql_insert_id() {
        $query  =   "SELECT @@IDENTITY as last_insert_id";
        $result =   mssql_query($query, $this->_linkID);
        list($last_insert_id)   =   mssql_fetch_row($result);
        mssql_free_result($result);
        return $last_insert_id;
    }

    /**
     * 启动事务
     * @access public
     * @return void
     */
    public function startTrans() {
        $this->initConnect(true);
        if ( !$this->_linkID ) return false;
        //数据rollback 支持
        if ($this->transTimes == 0) {
            mssql_query('BEGIN TRAN', $this->_linkID);
        }
        $this->transTimes++;
        return ;
    }

    /**
     * 用于非自动提交状态下面的查询提交
     * @access public
     * @return boolen
     */
    public function commit() {
        if ($this->transTimes > 0) {
            $result = mssql_query('COMMIT TRAN', $this->_linkID);
            $this->transTimes = 0;
            if(!$result){
                $this->error();
                return false;
            }
        }
        return true;
    }

    /**
     * 事务回滚
     * @access public
     * @return boolen
     */
    public function rollback() {
        if ($this->transTimes > 0) {
            $result = mssql_query('ROLLBACK TRAN', $this->_linkID);
            $this->transTimes = 0;
            if(!$result){
                $this->error();
                return false;
            }
        }
        return true;
    }

    /**
     * 获得所有的查询数据
     * @access private
     * @return array
     */
    private function getAll() {
        //返回数据集
        $result = array();
        if($this->numRows >0) {
            while($row = mssql_fetch_assoc($this->queryID))
                $result[]   =   $row;
        }
        return $result;
    }

    /**
     * 取得数据表的字段信息
     * @access public
     * @return array
     */
    public function getFields($tableName) {
        $result =   $this->query("SELECT   column_name,   data_type,   column_default,   is_nullable
        FROM    information_schema.tables AS t
        JOIN    information_schema.columns AS c
        ON  t.table_catalog = c.table_catalog
        AND t.table_schema  = c.table_schema
        AND t.table_name    = c.table_name
        WHERE   t.table_name = '$tableName'");
        $info   =   array();
        if($result) {
            foreach ($result as $key => $val) {
                $info[$val['column_name']] = array(
                    'name'    => $val['column_name'],
                    'type'    => $val['data_type'],
                    'notnull' => (bool) ($val['is_nullable'] === ''), // not null is empty, null is yes
                    'default' => $val['column_default'],
                    'primary' => false,
                    'autoinc' => false,
                );
            }
        }
        return $info;
    }

    /**
     * 取得数据表的字段信息
     * @access public
     * @return array
     */
    public function getTables($dbName='') {
        $result   =  $this->query("SELECT TABLE_NAME
            FROM INFORMATION_SCHEMA.TABLES
            WHERE TABLE_TYPE = 'BASE TABLE'
            ");
        $info   =   array();
        foreach ($result as $key => $val) {
            $info[$key] = current($val);
        }
        return $info;
    }

	/**
     * order分析
     * @access protected
     * @param mixed $order
     * @return string
     */
    protected function parseOrder($order) {
        return !empty($order)?  ' ORDER BY '.$order:' ORDER BY rand()';
    }

    /**
     * limit
     * @access public
     * @return string
     */
    public function parseLimit($limit) {
		if(empty($limit)) return '';
        $limit	=	explode(',',$limit);
        if(count($limit)>1)
            $limitStr	=	'(T1.ROW_NUMBER BETWEEN '.$limit[0].' + 1 AND '.$limit[0].' + '.$limit[1].')';
		else
            $limitStr = '(T1.ROW_NUMBER BETWEEN 1 AND '.$limit[0].")";
        return 'WHERE '.$limitStr;
    }

   /**
     * 更新记录
     * @access public
     * @param mixed $data 数据
     * @param array $options 表达式
     * @return false | integer
     */
    public function update($data,$options) {
        $this->model  =   $options['model'];
        $sql   = 'UPDATE '
            .$this->parseTable($options['table'])
            .$this->parseSet($data)
            .$this->parseWhere(isset($options['where'])?$options['where']:'')
            .$this->parseLock(isset($options['lock'])?$options['lock']:false);
        return $this->execute($sql);
    }

    /**
     * 删除记录
     * @access public
     * @param array $options 表达式
     * @return false | integer
     */
    public function delete($options=array()) {
        $this->model  =   $options['model'];
        $sql   = 'DELETE FROM '
            .$this->parseTable($options['table'])
            .$this->parseWhere(isset($options['where'])?$options['where']:'')
            .$this->parseLock(isset($options['lock'])?$options['lock']:false);
        return $this->execute($sql);
    }

    /**
     * 关闭数据库
     * @access public
     */
    public function close() {
        if ($this->_linkID){
            mssql_close($this->_linkID);
        }
        $this->_linkID = null;
    }

    /**
     * 数据库错误信息
     * 并显示当前的SQL语句
     * @access public
     * @return string
     */
    public function error() {
        $this->error = mssql_get_last_message();
        if('' != $this->queryStr){
            $this->error .= "\n [ SQL语句 ] : ".$this->queryStr;
        }
        trace($this->error,'','ERR');
        return $this->error;
    }
}