select datediff(M, lastupdatedate, datediff(M, lastupdatedate, Left(CONVERT(VARCHAR, GETDATE(), 121),10)) ) from table

怎么把 下面sqlserver 的sql 语句转换为 oracle pl/sql 写法？

 

select datediff(M, lastupdatedate, datediff(M, lastupdatedate, Left(CONVERT(VARCHAR, GETDATE(), 121),10)) )  from table