equivalent to INSERT INTO TABLE SET in Oracle - oracle11g

Question

I want to add data to table STATISTICS using INSERT statements.
I also want to move new counts to old counts and new date to old date as the new data comes in.
This is where it gets lil tricky because I don't know if there is such a thing as INSERT INTO table with SET in Oracle.
INSERT INTO STATISTICS
SET
MODEL = '&MY_MODEL',
NEW_COUNT =
(
SELECT COUNT(*)
FROM TABLE CLIENTS
),
NEW_DATE = SYSDATE,
OLD_COUNT = NEW_COUNT,
OLD_DATE = NEW_DATE,
PRNCT_CHANGE = ((NEW_COUNT) - (OLD_COUNT)) / (NEW_COUNT)*100
);
How do I accomplish this in Oracle?

Answer 1

This should upsert statistics, adding new ones as you go. It presumes a unique key on MODEL; if that's not true, then you'd have to do inserts as Angelina said, getting only the most recent row for a single MODEL entry.
MERGE INTO STATISTICS tgt
using (SELECT '&MY_MODEL' AS MODEL,
(SELECT COUNT(*) FROM CLIENTS) AS NEW_COUNT,
SYSDATE AS DATE_COUNT,
NULL AS OLD_COUNT,
NULL OLD_DATE,
NULL AS PRCNT_CHANGE
FROM DUAL) src
on (TGT.MODEL = SRC.MODEL)
WHEN MATCHED THEN UPDATE
SET TGT.NEW_COUNT = SRC.NEW_COUNT,
TGT.NEW_DATE = SRC.NEW_DATE,
TGT.OLD_COUNT = TGT.NEW_COUNT,
TGT.OLD_DATE = TGT.NEW_DATE,
TGT.PRCNT_CHG = 100 * (SRC.NEW_COUNT - TGT.NEW_COUNT) / (SRC.NEW_COUNT)
-- NEEDS DIV0/NULL CHECKING
WHEN NOT MATCHED THEN INSERT
(MODEL, NEW_COUNT, NEWDATE, OLD_COUNT, OLD_DATE, PRCNT_CHANGE)
VALUES
(src.MODEL, src.NEW_COUNT, src.NEWDATE, src.OLD_COUNT, src.OLD_DATE, src.PRCNT_CHANGE);

Answer 2

INSERT INTO STATISTICS(MODEL,NEW_COUNT,NEW_DATE,OLD_COUNT,OLD_DATE,PRNCT_CHANGE)
SELECT MODEL,
( SELECT COUNT(*)
FROM TABLE(USERS)
),
SYSDATE,
NEW_COUNT,
NEW_DATE,
(((NEW_COUNT) - (OLD_COUNT)) / (NEW_COUNT)*100)
FROM SEMANTIC.COUNT_STATISTICS
WHERE MODEL = '&MY_MODEL'
AND trunc(NEW_DATE) = trunc(NEW_DATE -1)
;