I have two tables from the database and I want to get the last status of each id. Tried adding the INNER JOIN claus but no avail. These are what my data looks like:
Table: employee
id name department
-------------------------
1 A X
2 B Y
3 C Z
Table: timelog
id time status count
-------------------------------
1 08:51 IN 1
3 09:00 OUT 2
2 09:00 IN 3
2 18:00 OUT 4
1 18:05 OUT 5
Currently, this is the query that I use but need to get the name of each employee.
SELECT
*
FROM timelog
WHERE timelog.count
IN (SELECT MAX(timelog.count)
FROM timelog
GROUP BY timelog.id)
ORDER BY clock.id;
Current output:
id time status
-------------------------------
1 18:05 OUT
2 18:00 OUT
3 09:00 OUT
This is the output I want to achieve:
id name time status
-------------------------------
1 A 18:05 OUT
2 B 18:00 OUT
3 C 09:00 OUT
Is it possible to add JOIN to the above query? If no, what would be the workaround? Any help would be greatly appreciated. TIA.
You can join the tables and use a correlated subquery for filtering:
select
e.id,
e.name,
t.time,
t.status
from employee e
inner join timelog t on t.id = e.id
where t.count = (
select max(count)
from timelog t1
where t1.id = t.id
)
Use a correlated subquery to get the last record for each id
in timelog
:
SELECT e.*, tl.*
FROM employee e JOIN
timelog tl
ON e.id = tl.id
WHERE tl.count = (SELECT MAX(tl2.count)
FROM timelog tl2
WHERE tl2.id = tl.id
) ;
Note that your version of the query is not correct. The subquery returns the maximum count for each id. However, the outer query might match a different id to the count in the subquery. The correlation clause fixes this problem.
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