Oracle SQL - update 2 columns in row with the oldest date - sql

Question

I am attempting to update 2 columns in a row. The row that should be updated is the row that has the oldest duedate
The table chorecompletion is described as:
Name Null? Type
----------------------------------------- -------- ----------------------------
CHOREID NOT NULL NUMBER(38)
GROUPID NOT NULL NUMBER(38)
DUEDATE NOT NULL DATE
COMPLETEDDATE DATE
COMPLETEDBY NUMBER(38)
This query returns the row that I want to update
select *
from
(
select choreid, duedate, row_number()
over (partition by choreid order by duedate) as rn
from chorecompletion where choreid = 12 and groupid = 6
)
where rn = 1;
Where I could use some help is how to use this query in my update statement, specifically my where clause
my current attempt:
update chorecompletion
set completeddate = sysdate, completedby=1
where --How to get the result of the previous query here?
Any help on my logic would be hugely appreciated.
Example desired result:
Before Update:
CHOREID GROUPID DUEDATE COMPLETEDDATE COMPLETEDBY
-------------------------------------------------------------------
12 6 2018-11-1
12 6 2018-10-1
After Update
CHOREID GROUPID DUEDATE COMPLETEDDATE COMPLETEDBY
-------------------------------------------------------------------
12 6 2018-11-1
12 6 2018-10-1 2018-09-30 1

Answer 1

Something like this?
SQL> create table test
2 (choreid number,
3 groupid number,
4 duedate date,
5 completeddate date,
6 completedby number
7 );
Table created.
SQL> insert into test
2 select 12, 6, date '2018-01-11', null, null from dual union all
3 select 12, 6, date '2018-01-10', null, null from dual;
2 rows created.
SQL> update test t set
2 t.completeddate = sysdate,
3 t.completedby = 1
4 where t.duedate = (select min(t1.duedate)
5 from test t1
6 where t1.choreid = t.choreid
7 and t1.groupid = t.groupid)
8 and t.choreid = 12
9 and t.groupid = 6;
1 row updated.
SQL> select * From test;
CHOREID GROUPID DUEDATE COMPLETEDD COMPLETEDBY
---------- ---------- ---------- ---------- -----------
12 6 2018-01-11
12 6 2018-01-10 2018-09-30 1
SQL>

Answer 2

You can use a MERGE statement and can join on the ROWID pseudo-column so that you can correlated directly to the matched row:
SQL Fiddle
Oracle 11g R2 Schema Setup:
CREATE TABLE chorecompletion ( choreid, groupid, duedate, completeddate, completedby ) AS
SELECT 12, 6, DATE '2018-09-29', CAST( null AS DATE ), CAST( null AS NUMBER ) FROM DUAL UNION ALL
SELECT 12, 6, DATE '2018-09-30', null, null FROM DUAL;
Query 1:
MERGE INTO chorecompletion dst
USING (
SELECT ROWID AS rid
FROM (
SELECT *
FROM chorecompletion
WHERE choreid = 12
AND groupid = 6
ORDER BY duedate ASC
)
WHERE ROWNUM = 1
) src
ON ( src.RID = dst.ROWID )
WHEN MATCHED THEN
UPDATE
SET completeddate = sysdate,
completedby = 1
Results:
1 Row Updated.
Query 2:
SELECT * FROM chorecompletion
Results:
| CHOREID | GROUPID | DUEDATE | COMPLETEDDATE | COMPLETEDBY |
|---------|---------|----------------------|----------------------|-------------|
| 12 | 6 | 2018-09-29T00:00:00Z | 2018-09-30T18:42:45Z | 1 |
| 12 | 6 | 2018-09-30T00:00:00Z | (null) | (null) |
Query 3: You could also use an UPDATE statement with the ROWID pseudo-column:
UPDATE chorecompletion dst
SET completeddate = sysdate,
completedby = 2
WHERE ROWID = (
SELECT ROWID
FROM (
SELECT ROW_NUMBER() OVER ( PARTITION BY choreid ORDER BY duedate ) rn
FROM chorecompletion
WHERE choreid = 12
AND groupid = 6
ORDER BY duedate ASC
)
WHERE rn = 1
)
Results:
1 Row Updated.
Query 4:
SELECT * FROM chorecompletion
Results:
| CHOREID | GROUPID | DUEDATE | COMPLETEDDATE | COMPLETEDBY |
|---------|---------|----------------------|----------------------|-------------|
| 12 | 6 | 2018-09-29T00:00:00Z | 2018-09-30T18:42:45Z | 2 |
| 12 | 6 | 2018-09-30T00:00:00Z | (null) | (null) |

Answer 3

You can use a correlated subquery. If I understand correctly:
update chorecompletion
set completeddate = (select min(duedate)
from chorecompletion cc
where cc.choreid = chorecompletion.coreid
)
where choreid = 12 and groupid = 6