subquery in FROM must have an alias

Question

I have this query I have written in PostgreSQL that returns an error saying:

[Err] ERROR:
LINE 3: FROM (SELECT DISTINCT (identifiant) AS made_on

Answer 1

add an ALIAS on the subquery,

SELECT  COUNT(made_only_recharge) AS made_only_recharge
FROM    
    (
        SELECT DISTINCT (identifiant) AS made_only_recharge
        FROM cdr_data
        WHERE CALLEDNUMBER = '0130'
        EXCEPT
        SELECT DISTINCT (identifiant) AS made_only_recharge
        FROM cdr_data
        WHERE CALLEDNUMBER != '0130'
    ) AS derivedTable                           -- <<== HERE