Question

I am running a query from pgAdmin3 against my postgresql database. I am wondering why it is returning values but all expected values. The query is:

SELECT P.SURNAME, 
       TO_CHAR(TO_DATE(SFE.GRANTDATE,'YYYY-MM-DD'),'DD Mon YY') AS GRANTDATE,
       TO_CHAR(TO_DATE(SFE.REVOKEDATE,'YYYY-MM-DD'),'DD Mon YY') AS REVOKEDATE, 
       SFE.feedname  
FROM   SYS_FEED SFE,
       PRINCIPLE P
WHERE  SFE.USERID = P.ID   
AND    to_date(GRANTDATE,'YYYY-MM-DD') <= to_date('Nov-2006','Mon-YYYY')

The GRANTDATE column is type date and contains values in the format 2006-09-04. I want to return all rows where the GRANTDATE is less than or equal to the month-year provided. The problem i have is that it returns all the “less than” matching rows but does not return the “equals to” rows. So Jan-2006 to Oct-2006 is there but not Nov-2006.

Any advice would be great.

Answer 1

Try:

SELECT P.SURNAME, 
       TO_CHAR(TO_DATE(SFE.GRANTDATE,'YYYY-MM-DD'),'DD Mon YY') AS GRANTDATE,
       TO_CHAR(TO_DATE(SFE.REVOKEDATE,'YYYY-MM-DD'),'DD Mon YY') AS REVOKEDATE, 
       SFE.feedname  
FROM   SYS_FEED SFE,
       PRINCIPLE P
WHERE  SFE.USERID = P.ID   
AND    to_date(GRANTDATE,'YYYY-MM-DD') < (to_date('Nov-2006','Mon-YYYY') + interval '1 month');

The problem: When you do to_date('Nov-2006','Mon-YYYY') you get the 2006-11-01. So the only date, that will be equal to to_date('Nov-2006','Mon-YYYY') is 2006-11-01, not the whole month.

Edit. The other way:

SELECT P.SURNAME, 
       TO_CHAR(TO_DATE(SFE.GRANTDATE,'YYYY-MM-DD'),'DD Mon YY') AS GRANTDATE,
       TO_CHAR(TO_DATE(SFE.REVOKEDATE,'YYYY-MM-DD'),'DD Mon YY') AS REVOKEDATE, 
       SFE.feedname  
FROM   SYS_FEED SFE,
       PRINCIPLE P
WHERE  SFE.USERID = P.ID   
AND    date_trunc('month', to_date(GRANTDATE,'YYYY-MM-DD')) <= to_date('Nov-2006','Mon-YYYY');