Driver_Database_Driver_MySQL::query

public function query($sql, $as_object=null, $use_connection_type=null)
{
    $sql = trim($sql);

    if (preg_match('#^([a-z]+)(:? |\n|\r)#i',$sql,$m))
    {
        $type = strtoupper($m[1]);
    }
    $typeArr = array
    (
        'SELECT',
        'SHOW',     //显示表
        'EXPLAIN',  //分析
        'DESCRIBE', //显示结结构
        'INSERT',
        'REPLACE',
        'UPDATE',
        'DELETE',
    );
    if (!in_array($type, $typeArr))
    {
        $type = 'MASTER';
    }
    $slaverType = array('SELECT', 'SHOW', 'EXPLAIN');
    if ($type!='MASTER' && in_array($type, $slaverType))
    {
        if (true===$use_connection_type)
        {
            $use_connection_type = 'master';
        }
        else if (is_string($use_connection_type))
        {
            if (!preg_match('#^[a-z0-9_]+$#i',$use_connection_type))$use_connection_type = 'master';
        }
        else
        {
            $use_connection_type = 'slaver';
        }
    }
    else
    {
        $use_connection_type = 'master';
    }

    # 设置连接类型
    $this->_set_connection_type($use_connection_type);

    # 连接数据库
    $connection = $this->connection();

    # 记录调试
    if(IS_DEBUG)
    {
        Core::debug()->info($sql,'MySQL');

        static $is_sql_debug = null;

        if (null === $is_sql_debug) $is_sql_debug = (bool)Core::debug()->profiler('sql')->is_open();

        if ($is_sql_debug)
        {
            $host = $this->_get_hostname_by_connection_hash($this->connection_id());
            $benchmark = Core::debug()->profiler('sql')->start('Database', 'mysql://' . ($host['username']?$host['username'].'@':'') . $host['hostname'] . ($host['port'] && $host['port'] != '3306' ? ':' . $host['port'] : ''));
        }
    }

    static $is_no_cache = null;
    if (null === $is_no_cache) $is_no_cache = (bool)Core::debug()->profiler('nocached')->is_open();
    //显示无缓存数据
    if ($is_no_cache && strtoupper(substr($sql, 0, 6)) == 'SELECT')
    {
        $sql = 'SELECT SQL_NO_CACHE' . substr($sql, 6);
    }

    // Execute the query
    if (($result = mysql_query($sql, $connection)) === false)
    {
        if (isset($benchmark))
        {
            // This benchmark is worthless
            $benchmark->delete();
        }

        if (IS_DEBUG)
        {
            $err = 'Error:' . mysql_error($connection) . '. SQL:' . $sql;
        }
        else
        {
            $err = mysql_error($connection);
        }
        throw new Exception($err, mysql_errno($connection));
    }

    if (isset($benchmark))
    {
        # 在线查看SQL情况
        if ($is_sql_debug)
        {
            $data = array();
            $data[0]['db']            = $host['hostname'] . '/' . $this->config['connection']['database'] . '/';
            $data[0]['select_type']   = '';
            $data[0]['table']         = '';
            $data[0]['key']           = '';
            $data[0]['key_len']       = '';
            $data[0]['Extra']         = '';
            $data[0]['query']         = '';
            $data[0]['type']          = '';
            $data[0]['id']            = '';
            $data[0]['row']           = count($result);
            $data[0]['ref']           = '';
            $data[0]['all rows']      = '';
            $data[0]['possible_keys'] = '';

            if (strtoupper(substr($sql,0,6))=='SELECT')
            {
                $re = mysql_query('EXPLAIN ' . $sql, $connection);
                $i = 0;
                while (true == ($row = mysql_fetch_array($re , MYSQL_NUM)))
                {
                    $data[$i]['select_type']      = (string)$row[1];
                    $data[$i]['table']            = (string)$row[2];
                    $data[$i]['key']              = (string)$row[5];
                    $data[$i]['key_len']          = (string)$row[6];
                    $data[$i]['Extra']            = (string)$row[9];
                    if ($i==0) $data[$i]['query'] = '';
                    $data[$i]['type']             = (string)$row[3];
                    $data[$i]['id']               = (string)$row[0];
                    $data[$i]['ref']              = (string)$row[7];
                    $data[$i]['all rows']         = (string)$row[8];
                    $data[$i]['possible_keys']    = (string)$row[4];
                    $i++;
                }
            }

            $data[0]['query'] = $sql;
        }
        else
        {
            $data = null;
        }
        Core::debug()->profiler('sql')->stop($data);
    }

    // Set the last query
    $this->last_query = $sql;

    if ($type === 'INSERT' || $type === 'REPLACE')
    {
        // Return a list of insert id and rows created
        return array
        (
            mysql_insert_id($connection),
            mysql_affected_rows($connection)
        );
    }
    elseif ($type === 'UPDATE' || $type === 'DELETE')
    {
        // Return the number of rows affected
        return mysql_affected_rows($connection);
    }
    else
    {
        // Return an iterator of results
        return new Database_Driver_MySQL_Result($result, $sql, $as_object, $this->config);
    }
}