Sql get MAX for other value
I would like to figure out how to select a table where the value is the ID of the person with the highest pay.
So if开发者_Python百科 I had
Table=theJobs
JobID Pay
----------
12345 10
12346 12
12347 13
table=thePerson
Person JobID
--------------
Person1 1
Person2 2
Person3 3
table=hire(FKs)
JobID PersonID
----------------
12345 2
12347 1
12346 3
I'd like it to show the max payed person so it should show
Person1
I tried to use where for the a Max function but it seems to fail. I'm pretty sucky at these group functions. I guess I'm more asking how to use a group function as a constraint than anything. Since I had a similar issue a bit ago.
This solution will work in pretty much any database system:
Select ....
From thePerson As P
Join (
Select H1.PersonId, Max( J1.Pay ) As MaxPay
From hire As H1
Join theJobs As J1
On J1.JobId = H1.JobID
Group By H1.PersonId
) As PayPerPerson
On PayPerPerson.PersonId = P.Person
Where Exists (
Select 1
From hire As H2
Join theJobs As J2
On J2.JobId = H2.JobID
Where H2.PersonId = P.Person
Having Max( J2.Pay ) = PayPerPerson.MaxPay
)
If you are using a DBMS that supports ranking functions and common-table expressions such as SQL Server 2005 and later, then the problem is easier. This solution will show only one name and ignore ties:
With RankedPay As
(
Select ...
, Row_Number() Over( Order By J.Pay Desc ) As Rnk
From thePerson As P
Join hire As H
On H.PersonId = P.Person
Join theJobs As J
On J.JobId = H.JobId
)
Select ...
From RankedPay
Where Rnk = 1
This solution will show any that match the top pay and include ties:
With RankedPay As
(
Select ...
, Rank() Over( Order By J.Pay Desc ) As Rnk
From thePerson As P
Join hire As H
On H.PersonId = P.Person
Join theJobs As J
On J.JobId = H.JobId
)
Select ...
From RankedPay
Where Rnk = 1
SELECT p.Person
FROM person p JOIN hire h ON p.PersonID = h.PersonID
JOIN theJobs j ON h.JobID = j.JobID
ORDER BY j.Pay DESC
LIMIT 1;
If you are using a RDBMS that does not support the LIMIT
clause, try using the TOP
clause instead:
SELECT TOP 1 p.Person
FROM person p JOIN hire h ON p.PersonID = h.PersonID
JOIN theJobs j ON h.JobID = j.JobID
ORDER BY j.Pay DESC
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