【PHP】SQL Server 數據庫類（適用於win mssql擴展及freetds擴展）

<?php
if(!defined('IN_WOGU')) {
	exit('Access Denied');
}

/**
 * SQL Server 數據庫操作類,基於MSSQL擴展（或FreeTDS）
 *
 * Mssql類的默認配置
 * $default = array(
 *		'servername'    => '',//服務器名
 *		'username'      => '',//用戶名
 *		'password'      => '',//密碼
 *		'database'      => '',//數據庫名
 *		'table_pre'     => '',//表前輟
 *		'new_link'      => false,//是否創建新的數據庫連接
 *		'autoconnect'   => true,//是否自動連接，爲false時爲lazy load模式
 *		'debug'         => false,//是否啓用debug
 *		//其它數據庫的(使用selectDB切換的)的表前輟映射表
 *		'map'           => array(
 *			//'dbname' => 'this db table pre'
 *		)
 *	)
 *
 * 使用Mssql
 * $db = new Mssql();
 * $db->open(array(
 *		'servername' => 'KALLESPC\SQLEXPRESS',
 *		'username'   => 'sa',
 *		'password'   => 'phpfi',
 *		'database'   => 'php',
 *		'table_pre'  => 'table_pre',
 *		'map'        => array(
 *			'otherdb' => 'otherdbpre_'
 *		)
 * ));
 * //注意：這裏wogu_在內部將自動被處理成$this->_tablePre
 * $db->query('SELECT * FROM wogu_tablename WHERE id=1');
 * $r = $db->fetchArray();
 * print_r($r);
 *
 * @author wogu
 * @lastmodify 2011-11-9
 */

class Mssql
{
	protected $_link;
	protected $_config = array();
	protected $_lastError = '';
	protected $_lastqueryid = null;
	protected $_querycount = 0;
	protected $_tablePre;
	protected $_database;
	
	public function open(array $config) {
		$default = array(
			'servername'    => '',
			'username'      => '',
			'password'      => '',
			'database'      => '',
			'table_pre'     => '',
			'new_link'      => false,
			'autoconnect'   => true,
			'debug'         => false,
			'map'           => array()
		);

		$this->_config = array_merge($default, $config);
		if($this->_config['autoconnect'] == true) {
			return $this->_connect();
		}
	}
	
	private function _connect() {
		$this->_link = mssql_connect($this->_config['servername'], $this->_config['username'], $this->_config['password'], $this->_config['new_link']);
		
		if(!$this->_link) {
			return $this->_halt('Can\'t connect to SqlServer');
		}
		
		if(!empty($this->_config['database'])) {
			$this->selectDB($this->_config['database']);
		}
		
		return $this->_link;
	}
	
	public function selectDB($database_name) {
		$this->_database = $database_name;
		$this->_tablePre = empty($this->_config['map'][$database_name]) ? $this->_config['table_pre'] : $this->_config['map'][$database_name];
		return mssql_select_db($database_name, $this->_link);
	}
	
	private function _execute($sql) {
		if(!is_resource($this->_link)) {
			$this->_connect();
		}
		
		$sql = str_replace('wogu_', $this->_tablePre, $sql);
		$this->_lastqueryid = mssql_query($sql, $this->_link);
		
		if(!$this->_lastqueryid) {
			return $this->_halt('SqlServer query error', $sql);
		}

		$this->_querycount++;
		return $this->_lastqueryid;
	}
	
	public function query($query) {
		return $this->_execute($query);
	}
	
	public function fetchArray($result_type = MSSQL_ASSOC) {
		$res = mssql_fetch_array($this->_lastqueryid, $result_type);
		
		if(!$res) {
			$this->freeResult();
		}
		
		return $res;
	}
	
	public function freeResult() {
		if(is_resource($this->_lastqueryid)) {
			mssql_free_result($this->_lastqueryid);
			$this->_lastqueryid = null;
		}
	}
	
	public function affectedRows() {
		return mssql_rows_affected($this->_lastqueryid);	
	}
	
	/**
	 * 默認返回一行，當$col>=0時返回該行的某一列
	 * @param string $sql 查詢語句
	 * @param int $col 列號
	 * @return mixed
	 */
	public function fetchOne($sql, $col = -1) {
		$this->_execute($sql);
		$res = $this->fetchArray();
		$this->freeResult();
		
		return $col >= 0 ? $res[$col] : $res;
	}
	
	public function insert($table, $data, $return_insert_id = false) {
		if(!is_array( $data ) || $table == '' || count($data) == 0) {
			return false;
		}
		
		$valuedata = array_values($data);
		array_walk($valuedata, array($this, 'escape'));
		
		$field = implode (',', array_keys($data));
		$value = implode (',', $valuedata);
		
		$sql = 'INSERT INTO ' . $this->config['database'] . '.' . $table . ' (' . $field . ') VALUES (' . $value . ')';
		$return = $this->execute($sql);
		return $return_insert_id ? $this->lastInsertId() : $return;
	}
	
	public function update($data, $table, $where = '') {
		if($table == '' or $where == '') {
			return false;
		}

		$where = ' WHERE '.$where;
		$field = '';
		if(is_string($data) && $data != '') {
			$field = $data;
		} elseif (is_array($data) && count($data) > 0) {
			$fields = array();
			foreach($data as $k=>$v) {
				switch (substr($v, 0, 2)) {
					case '+=':
						$v = substr($v,2);
						if (is_numeric($v)) {
							$fields[] = $k.'='.$k.'+'.$v;
						} else {
							continue;
						}
						
						break;
					case '-=':
						$v = substr($v,2);
						if (is_numeric($v)) {
							$fields[] = $k.'='.$k.'-'.$v;
						} else {
							continue;
						}
						break;
					default:
						$fields[] = $k.'='.$this->escape($v);
				}
			}
			$field = implode(',', $fields);
		} else {
			return false;
		}

		$sql = 'UPDATE wogu_'.$table.' SET '.$field.$where;
		return $this->_execute($sql);
	}
	
	/**
	 * 只考慮數字和字符串的情形，bool,object等類型本身就是錯誤的
	 * @param mix $value 待處理變量
	 * @return mix
	 */
	public function escape(&$value, $key = '') {
		if(is_string($value)) {
			$value = '\'' . $value . '\'';
		}
		
		return $value;
	}

	public function lastInsertId() {
	    $sql = 'SELECT SCOPE_IDENTITY()';
	    return (int)$this->fetchOne($sql, 0);
	}
	
	public function set_debug($flag) {
		$this->_config['debug'] = $flag;
	}
	
	protected function _halt($message = '', $sql = '') {
		$this->_lastError = mssql_get_last_message();
		
		if($this->_config['debug']) {
			$errormsg = "<b>Message : </b> $message<br><b>Mssql Query : </b> $sql <br /><b> Mssql Error : </b>" . $this->_lastError;
			echo '<div style="font-size:12px;text-align:left; border:1px solid #9cc9e0; padding:1px 4px;color:#000000;font-family:Arial, Helvetica,sans-serif;"><span>' . $errormsg . '</span></div>';
			exit;
		}
		
		return false;
	}
	
	public function getLastMessage() {
		return $this->_lastError;
	}
	
	public function getLink() {
		return $this->_link;
	}
	
	public function getQueryCount() {
		return $this->_querycount;	
	}
}