You can not to have a duplicate records in the new table if you put an index, (unique = Yes).
HI MStef. Thank you so much for the help. Now my database has no duplicate entries. May i also ask another thing? Is it possible to edit the data once it was already entered in the database? For example i mistakenly entered wrong work order and i found it in the summary when i finished the data entry. How can i undo my last encoding and edit?