Shrinking SQL .MDF & LDF file size not working?

Hi All,

May I know what's the command to shrink down the .MDF and .LDF files?

Because when I execute this command below, it does not reduce the disk space used, even after I purge some of the old data content.

ALTER DATABASE AppDB SET RECOVERY SIMPLE
GO

DBCC SHRINKFILE (N'AppDB_log' , 0, TRUNCATEONLY)
GO
DBCC SHRINKFILE (N'AppDB' , 0, TRUNCATEONLY)
GO

Thank you in advance.

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