Hi Mª João,
If you want to import tables from an existing database check this help topic. OutSystems Platform will infer the primary keys as long as they are supported, i.e. it won't import primary keys composed of multiple attributes.
As for constraints those are created for foreign keys depending on the delete rule value for that specific attribute. The mandatory property attribute is used as meta-information for the platform to perform validations in forms. Therefore it is important that you secure in your logic the data that you send to the database againts all business rules, either by checking that the form is valid upon submit and any other biz rules that apply.
I hope this helps,
Cheers
If you want to import tables from an existing database check this help topic. OutSystems Platform will infer the primary keys as long as they are supported, i.e. it won't import primary keys composed of multiple attributes.
As for constraints those are created for foreign keys depending on the delete rule value for that specific attribute. The mandatory property attribute is used as meta-information for the platform to perform validations in forms. Therefore it is important that you secure in your logic the data that you send to the database againts all business rules, either by checking that the form is valid upon submit and any other biz rules that apply.
I hope this helps,
Cheers