How do I split flat file data and load into parent-child tables in database?

Question

I have denormalized data (coming from a file) that needs to be imported into parent-child tables. The source data is something like this:

Account#    Name           


        

Answer 1

If the data is sorted and Account# is an integer I would:

Insert the emails into a table (add an auto increment column, it's a best practise).

1  101    alpha@foo.com
2  101    bravo@foo.com
3  101    charlie@yay.com
etc.

Then I would insert the other records to a parent table.

• using Account# as the primary key
• omitting the email addresses
• skipping duplicates (easy if the data is sorted).

If you have a foreign key relationship setup, you will need to do the second step first (to avoid having any orphan records).

My two cents: I don't know what your requirements are but it seems a bit over-normalized. If there is a small limit on the number of email addresses, I would consider adding several email columns to the main table...for speed and simplicity.