deleting records with foreign key elements - sql
I have 3 tables that have foreign keys linked to each other. When I opened the first table to delete a row, it would not let me because I have the keys linked to the other tables. How do I delete records?
Juan Ocasio
You have to first delete the records in the other tables that are linked to that record. This foreign key is ensuring data integrity in your db and the constraint won't allow you to delete the record if records in other tables are associated with it.
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ASKER
is that the main purpose of the foreign key?
To me, I think I can control that without needing it through Visual Basic.
To me, I think I can control that without needing it through Visual Basic.
You can always control it in code, but it only takes one person to write some invalid code to trash your database.
I would always use keys, but it is the subject of debate. However there is very little bad about them, a very minor performance hit that will probably never notice. Versus lots of things that could go wrong with bad data, maybe not today, but later when someone else doesn't understand your code :)
However if I ever decided not to use keys I would require all inserts/updates/deletes to be carried out via a database stored procedure to prevent coding mistakes.
I would always use keys, but it is the subject of debate. However there is very little bad about them, a very minor performance hit that will probably never notice. Versus lots of things that could go wrong with bad data, maybe not today, but later when someone else doesn't understand your code :)
However if I ever decided not to use keys I would require all inserts/updates/deletes to be carried out via a database stored procedure to prevent coding mistakes.
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