# 4528 Altering a Table Results in an Incorrect Table Structure Checksum

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I get an checksum mismatch for a table, as soon I do an alter table without to alter anything at all. This will change the checksum and I'm not anymore able to restore that single table from the backup.

I have attached a small backup with empty tables to this email. So use this steps to reproduce it:

1. Create a new empty database.
2. Restore the attached Backup inluding the schema to this database.
3. Now again restore the backup but this time without the schema and only the single table Accessories.

This works fine as excepted.

4. Now open the Alter table dialog in edbmgr.exe and confirm with OK, without to do any changes. This will change the checksum incorrectly!
5. Now again try to restore only the Accessories table from the backup.

Now you get an checksum error and you are not anymore able to restore the Accessories table alone form the backup. The schema is still the same but the checksum calculation is wrong as of a bug in TEDBVirtualTable.Save routine.