UPDATE all values of a column with a single value, if that value is present, for all users

Question

I have table like this:

ID | cur_val | done  | res 
1  | 10000   | false | false
2  | 20000   | false | false
3  | 30000   | false | false
1  | 40000   | false | false
3  | 60000   | false | false
1  | 10000   | true  | false

I need an update query to update the res column (which is false by default) depending on the values from the done column. Specifically, for any ID , if done is true , then all the res values associated with that ID should be updated to true .

The final table should look like this:

ID | cur_val | done  | res 
1  | 10000   | false | true
2  | 20000   | false | false
3  | 30000   | false | false
1  | 40000   | false | true
3  | 60000   | false | false
1  | 10000   | true  | true

I'd appreciate any help with this.

Answer 1

in sql server

UPDATE t1
SET res = 1
FROM yourtable t1
WHERE EXISTS
    (SELECT 1
     FROM yourtable t2
     WHERE t1.ID = t2.ID
       AND done = 1)

in postgres

UPDATE yourtable t1
SET res = true
WHERE EXISTS
    (SELECT 1
     FROM yourtable t2
     WHERE t1.id = t2.id
       AND done = true)
;