restore database a56_trial --新数据库名称
from disk='D:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\Backup\A56.20190806.bak' --备份文件
with RECOVERY,REPLACE,move 'a56' --老数据库mdf名称
to 'D:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\DATA\a56_trial.mdf', --mdf新路径
move 'a56_log' --老数据库ldf名称
to 'D:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\DATA\a56_trial_log.ldf'; --ldf新路径