Question

I have a table called datetest

CREATE TABLE "DATETEST"."DATETEST" 
   ("FNAME" VARCHAR2(20 BYTE), 
"DOB" DATE, 
"STAFFNO" NUMBER NOT NULL ENABLE, 
 CONSTRAINT "DATETEST_PK" PRIMARY KEY ("STAFFNO"));

with the following data

INSERT INTO "DATETEST"."DATETEST" (FNAME, DOB, STAFFNO) VALUES ('John', TO_DATE('01-   OCT-45', 'DD-MON-RR'), '1')
INSERT INTO "DATETEST"."DATETEST" (FNAME, DOB, STAFFNO) VALUES ('Ann', TO_DATE('01-NOV-60', 'DD-MON-RR'), '2')
INSERT INTO "DATETEST"."DATETEST" (FNAME, DOB, STAFFNO) VALUES ('David', TO_DATE('24-MAR-58', 'DD-MON-RR'), '3')
INSERT INTO "DATETEST"."DATETEST" (FNAME, DOB, STAFFNO) VALUES ('Mary', TO_DATE('19-FEB-70', 'DD-MON-RR'), '4')
INSERT INTO "DATETEST"."DATETEST" (FNAME, DOB, STAFFNO) VALUES ('Susan', TO_DATE('03-JUN-40', 'DD-MON-RR'), '5')
INSERT INTO "DATETEST"."DATETEST" (FNAME, DOB, STAFFNO) VALUES ('Julie', TO_DATE('13-JUN-65', 'DD-MON-RR'), '6')

when i do execute the following query

select * from datatest order by dob desc 

i get the following result

FNAME                DOB       STAFFNO
-------------------- --------- -------
John                 01-OCT-45       1 
Susan                03-JUN-40       5 
Mary                 19-FEB-70       4 
Julie                13-JUN-65       6 
Ann                  01-NOV-60       2 
David                24-MAR-58       3 

I cannot figure out how to get the correct order. How do I query the correct order?

Answer 1

Your data is in chronological order. The problem is that you are using ‘DD-MM-RRRR’ instead of ‘DD-MM-YY’ for the conversion.

The ‘RRRR’ version uses particular rules to get the century. So, your first row is 2045-10-01, not 1945-20-01.