Postgres 14

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

CREATE table data_table(ID INTEGER,  created_ts INTEGER, value INTEGER);

INSERT INTO data_table VALUES (1, 2, 3);
INSERT INTO data_table VALUES (3, 4, 5);
1 rows affected

1 rows affected

SELECT dt1.ID
           , dt1.created_ts
           , (SELECT value FROM data_table dt2 WHERE dt1.ID = dt2.ID ) AS value
        FROM data_table dt1


id
created_ts
value


1
2
3

3
4
5


SELECT dt1.ID
          , dt1.created_ts
          , dt2.value
       FROM data_table dt1 LEFT JOIN (SELECT value FROM data_table WHERE dt1.ID = data_table.ID ) dt2
ERROR:  syntax error at end of input
LINE 5: ...ECT value FROM data_table WHERE dt1.ID = data_table.ID ) dt2
                                                                       ^


SELECT dt1.ID, dt1.created_ts, dt2.value
FROM data_table dt1 LEFT JOIN data_table dt2
ON dt1.ID = dt2.ID


id
created_ts
value


1
2
3

3
4
5