intrvw qstn (only trigger not in constraint)

[zulu99]

Hi All

This is 1 of the intrvw question.

When will it be imperative to handle data integrity only in triggers and cannot be handled by in integrity constraints

i gave the answer say on certain holidays(sat & sun) i dont want to give users access to the databse tables.

What are others where we will have to manage data integrity only trhough triggers & cannot be done through integrity constraints

Rgrds

[stecal]

If you look at constraints checking for data, those check for validity of the data (is this the right type of data?), not whether the data shouldn't be put in.

If you look at the triggers for checking/enforcing business rules, those check for is it okay to put the data in (is now a good time, is this user allowed to insert/update/delete, are customer numbers allowed to be changed, etc?).