从 MediaStore 中删除一个文件条目的问题

我想从一个MediaStore中删除一个文件条目，使用的下面的代码：

noOfEntriesDeleted = contentResolver.delete(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
"_data=" + originalFile, null);

但是没有实现我所要的功能，输出下面的错误：

08-03 16:00:46.850: I/SqliteDatabaseCpp(5124): sqlite returned: error code = 1, msg = near "/": syntax error, db=xxx
08-03 16:00:46.860: E/DatabaseUtils(5124): Writing exception to parcel
08-03 16:00:46.860: E/DatabaseUtils(5124): android.database.sqlite.SQLiteException: near "/": syntax error: , while compiling: DELETE FROM files WHERE media_type=2 AND (_data=/mnt/sdcard/tmp/FILE_154050.3gp)

这是什么原因呢？

originalFile缺少单引号