In Oracle 10g, I have this SQL:
select dog.id as dogId from CANINES dog order by dog.codename asc
which returns:
id
--
204
203
206
923
I want to extend this query to determine the oracle rownum of a dog.id in this resultset.
I have tried
select rownum from
(select dog.id as dogId from CANINES dog order by dog.codename asc)
where dog.id=206
But this does not work out very well (it returns 1 no matter which dog.id I match on). I was expecting to get back 3.
Thanks for your help!
Notes
http://www.oracle.com/technology/oramag/oracle/06-sep/o56asktom.html
I am pretty sure I do not need to use rowid
I suspect what you want is to use an analytic function (RANK, DENSE_RANK
, or ROW_NUMBER
), i.e.
SELECT rnk
FROM (select dog.id as dogId,
ROW_NUMBER() OVER( ORDER BY dog.codename ASC ) rnk
from CANINES dog )
WHERE dogId = 206
If the ID column in the CANINES table were not unique, RANK, DENSE_RANK
, and ROW_NUMBER
) would treat ties differently.
If you want to do this solely with ROWNUM,
SELECT rn
FROM (
SELECT dogId, rownum rn
FROM (select dog.id as dogId
from CANINES dog
order by dog.codename ASC) inner
) middle
WHERE dogId = 206
If you're after the unique identifier of each row in the table you need ROWID, not ROWNUM.
ROWNUM is a pseudocolumn that can change each time a bit of SQL is executed (it's worked out at query time)
See if this works for you:
Answer
SELECT dog1.DogID, dog1.DogName, COUNT(*) AS rownumber
FROM #ids dog1, #ids dog2
WHERE dog2.DogName <= dog1.DogName
GROUP BY dog1.DogID, dog1.DogName
ORDER BY dog1.DogName
Results
DogID DogName rownumber
----------- ---------- -----------
204 Dog 1 1
203 Dog 2 2
206 Dog 3 3
923 Dog 4 4
DDL
CREATE TABLE #ids (DogID int NOT NULL PRIMARY KEY, DogName varchar(10) NOT NULL)
INSERT INTO #ids (DogID, DogName) VALUES (204, 'Dog 1')
INSERT INTO #ids (DogID, DogName) VALUES (203, 'Dog 2')
INSERT INTO #ids (DogID, DogName) VALUES (206, 'Dog 3')
INSERT INTO #ids (DogID, DogName) VALUES (923, 'Dog 4')
In order to accomplish this, it would be best to alter the table and add a sequence. This could get sticky if you intend to delete rows. Where, perhaps a better practice would be to use a status column or and start-end-date motif to decide which rows are active and should be returned.
来源:https://stackoverflow.com/questions/534217/sql-to-return-the-rownum-of-a-specific-row-using-oracle-db