SQL combine two records based on one value - sql

Question

Update - work done in SQL-92
I work in SQL reporting tool and trying to combine two records into one. Let's say there as some duplicates were time got split into two values and hence the duplication. Basically any values that are not duplicated should be added
wo---text---time---value
1----test---5------1
1----test---2------a
3----aaaa---3------1
4----bbbb---4------2
Results
wo---text---time----value
1----test---7--------1a
3----aaaa---3--------1
4----bbbb---4--------2
I tried:
SELECT ....
FROM ....
GROUP BY wo SUM (time) but that did not even work.

Answer 1

Set-up:
create table so48345659a
(
wo integer,
text varchar(4),
time integer,
value varchar(2)
);
create table so48345659b
(
wo integer,
text varchar(4),
time integer,
value varchar(2)
);
insert into so48345659a (wo, text, time, value) values (1, 'test', 5, '1');
insert into so48345659a (wo, text, time, value) values (1, 'test', 2, 'a');
insert into so48345659a (wo, text, time, value) values (3, 'aaaa', 3, '1');
insert into so48345659a (wo, text, time, value) values (4, 'bbbb', 4, '2');
insert into so48345659b (wo, text, time, value) values (1, 'test', 7, '1a');
insert into so48345659b (wo, text, time, value) values (3, 'aaaa', 3, '1');
insert into so48345659b (wo, text, time, value) values (4, 'bbbb', 4, '2');
Union, by default removes duplicates
select wo, text, time, value from so48345659a
union
select wo, text, time, value from so48345659b;
Result:
wo | text | time | value
----+------+------+-------
1 | test | 7 | 1a
1 | test | 2 | a
3 | aaaa | 3 | 1
1 | test | 5 | 1
4 | bbbb | 4 | 2
(5 rows)
So now run sum on the union
select
wo,
sum(time) as total_time
from
(
select wo, text, time, value from so48345659a
union
select wo, text, time, value from so48345659b
) x
group by
wo;
Result:
wo | total_time
----+------------
3 | 3
1 | 14
4 | 4
(3 rows)
From your supplementary question (22-Jan-2017), I guess you mean that you have one table that contains duplicate rows. Is that right?
If so, it might look like this:
select * from so48345659c;
wo | text | time | value
----+------+------+-------
1 | test | 5 | 1
1 | test | 2 | a
3 | aaaa | 3 | 1
4 | bbbb | 4 | 2
1 | test | 7 | 1a
3 | aaaa | 3 | 1
4 | bbbb | 4 | 2
(7 rows)
So then you get the sum of the times, ignoring duplicate rows, like this:
select
wo,
sum(time) as total_time
from
(
select distinct wo, text, time, value from so48345659c
) x
group by
wo;
wo | total_time
----+------------
3 | 3
1 | 14
4 | 4
(3 rows)

Answer 2

With just two values, you can do:
select wo, text, sum(time) as time, concat(min(value), max(value)) as value
from t
group by wo, text;
This uses the fact that the standard representation of 1 has a value less than a.
Most databases support string aggregation of some sort (group_concat(), listagg(), and string_agg() are typical functions). You can use one of these for a more general solution.