--只有mdf文件，没有ldf文件，可通过选项来恢复。FOR ATTACH_REBUILD_LOG;
--有日志文件则附加上，若无，则新建
CREATE DATABASE AdventureWorks2012
ON (FILENAME = 'M:\Program Files\Microsoft SQL Server201201\MSSQL11.MSSQLSERVER\MSSQL\DATA\AdventureWorks2012_Data.mdf')
FOR ATTACH_REBUILD_LOG;