"Francesco Formenti - TVBLOB S.r.l." <[EMAIL PROTECTED]> writes: > we are developing a system for profile management. The simplified schema > is composed by three tables:
> * tbl_user : the users table; contains the unique id of the users > and the profile id (only one profile for each user), and some > other information > * tbl_data_type : contains the data type of the profile, their id > and their names. E.g.: id=1, data type name="last name"; id=2, > data type name="address", and so on > * tbl_data : the data of all the profiles of the system; it has > three columns: the id of the profile the data belongs to (linked > to the tbl_user), the data type id (linked to tbl_data_type) and > the value of the data. E.g.: profile=1, data_type_1=1, > value="Smith", and so on I think you need to refactor your schema. You want to have one table that is clearly the "defining" table for profiles, and then put a unique constraint on that table's ID column, and probably foreign key constraints on other tables that mention profile IDs. It's not real clear to me why you're bothering with a separation between tbl_data_type and tbl_data, either ... regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org