Q:

how we delete a row from parent table when child table connected with paren table by forigen key

hi all i am getting a problem while i attenpting to delete a row from  parent table, actuall i have created 2 table  custmer and account.i make cutomer id(primary  key) in customer and customer id (forigen key ) in account.after created it i have filled data inside both table.
at this point while i am trying to delete a row from first table (customer ) then it give failure message is that it can't be deleted bcs it is refrenced as forigen key some thing like that............but while we delete row from account table then it's delete sucess fully.
.......i want to function like that if i delete a row from parent table(customer) then its in child table that row which has same customer id (account table) is delete automatically............

A:

watch out on the cascade deletes! a user will accidentally click on the application's little trash can icon and delete the customer, and then all the cascades will remove every trace of that customer, orders, invoices, payments, history, etc from your database.  After the user call you to tell you about their little mistake, you'll have to restore a backup and try to pull the info back into the database.
I would look into "soft deletes" where you only change the customer's status from "active" to "inactive".  the rows is not deleted, preserving all foreign key data.  This allows reports to run on the data, because it still exists, as well as easy an "undo".
Soft deletes are not the end all only way to go, it is a business decision on how to handle this, purge the data or mark it inactive.  That is only something you can decide, because I don't know your application or business logic.  I just thought that I would offer it as an alternative.

