> In my system a user can have external contacts. When I am > bringing in external contacts I want to correlate any other > existing users in the system with those external contacts. A > users external contacts may or may not be users in my system. I > have a user_id field in "contacts" that is NULL if that contact > is not a user in my system > > Currently I do something like this after reading in external > contacts: > > UPDATE contacts SET user_id = u.id > FROM my_users u > JOIN phone_numbers pn ON u.phone_significant = pn.significant > WHERE contacts.owner_id = 7 > AND contacts.user_id IS NULL > AND contacts.id = pn.ref_contact_id; > > If any of the fields are not self explanatory let me know. > "Significant" is just the right 7 most digits of a raw phone > number. > > I'm more interested in possible improvements to my relational > logic than the details of the "significant" condition. IOW, I'm > start enough to optimize the "significant" query but not smart > enough to know if this is the best approach for the overall > correlated UPDATE query. :) > > So yeah, is this the best way to update a contact's user_id > reference based on a contacts phone number matching the phone > number of a user? > > One detail from the schema -- A contact can have many phone > numbers but a user in my system will only ever have just one > phone number. Hence the JOIN to "phone_numbers" versus the column > in "my_users".
In looking it over, nothing jumped out at me as a problem. Are you having some problem with it, like poor performance or getting results different from what you expected? -- Kevin Grittner EDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
