CODEWITHSUNDEEP
sqlpostgresql
Mateusz Urbański
Mateusz Urbański

Reputation: 7862

Combine three columns in to one

I have the following sql statement:

SELECT p.id, p.first_name, p.last_name, a.admitted_at,
       a.discharged_at, c.name as client_name, p.receive_reminders,
       p.opt_in_to_receive_reminders, u.phone_number, p.status,
       c.id as client_id, p.mrn
  FROM patients p
  LEFT JOIN admissions a ON p.last_admission_id = a.id
  INNER JOIN facilities f ON f.id = p.facility_id
  INNER JOIN clients c ON c.id = f.client_id
  LEFT OUTER JOIN users u ON p.user_id = u.id;

I have three columns:

p.opt_in_to_receive_reminders - boolean
u.phone_number - string
p.receive_reminders - boolean

I want to combine result of this 3 columns in to one virtual column - messaging. For example if p.opt_in_to_receive_reminders is true and if u.phone_number is not empty and p.receive_reminders is true then this column will have true value, in other scenario it will return false.

How can I do this in PostgreSQL?

Upvotes: 0

Views: 86

Answers (1)

klin
klin

Reputation: 121524

Just write this:

p.opt_in_to_receive_reminders is true and if u.phone_number is not empty and p.receive_reminders is true

as

select p.opt_in_to_receive_reminders and u.phone_number is not null and p.receive_reminders
-- or
select p.opt_in_to_receive_reminders and u.phone_number <> '' and p.receive_reminders
-- or
select p.opt_in_to_receive_reminders and coalesce(u.phone_number, '') is null and p.receive_reminders

Upvotes: 3

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