How add lines to table?

[amator]

Hi. (I already ask how to delete rows but it looks too hard to make so I invent new idea)
How I can add lines (INSERT INTO) into table so that Access does not add lines which already are in the table??

 

[Pat Hartman]

Define a primary key. Access will not allow you to add duplicates.

 

[amator]

Thanks. But how I should set my keys to two tables(source table and destination table). I don't understand how I can prevent adding duplicated rows to my table by using primary key.

 

[Pat Hartman]

Primary keys control the contents of a single table. If you define a primary key for a table, you will not be able to add rows that duplicate that key. For example, if you create a table to hold parts and define PartNum to be the primary key. You will not be able to add a second row with a PartNum that duplicates an existing row.