CODEWITHSUNDEEP
oracle-databaserangeliteralsbetweensysdate
theRiley
theRiley

Reputation: 1167

Oracle between dates sysdate range vs literal date range

Here is the situation :

select sysdate from dual ;

>  30-APR-19

SELECT
  count(*)
FROM 
  event_log
WHERE
  edate between to_date('04232019', 'MMDDYYYY') and to_date('04292019', 'MMDDYYYY') ;

> 1156

SELECT
  count(*)
FROM 
  event_log
WHERE
  edate between (sysdate-7) and (sysdate-1) ;

> 1276

This is an event log, rows are date-tagged (row counts for previous days are static).

My question - why aren't the counts the same? What am i missing? Is there some semantic difference between the two ranges?

Upvotes: 0

Views: 37

Answers (1)

Littlefoot
Littlefoot

Reputation: 142705

SYSDATE is a function that returns both date and time component. If you don't TRUNCate it, you'd get both:

SQL> select sysdate,
  2         sysdate - 7 prev_week,
  3         sysdate - 1 yesterday
  4  from dual;

SYSDATE             PREV_WEEK           YESTERDAY
------------------- ------------------- -------------------
30.04.2019 23:13:14 23.04.2019 23:13:14 29.04.2019 23:13:14

SQL>

If you TRUNCate it, you'd get the midnight:

SQL> select trunc(sysdate) today,
  2         trunc(sysdate - 7) prev_week,
  3         trunc(sysdate - 1) yesterday
  4  from dual;

TODAY               PREV_WEEK           YESTERDAY
------------------- ------------------- -------------------
30.04.2019 00:00:00 23.04.2019 00:00:00 29.04.2019 00:00:00

SQL>

Which means that your last condition should, probably, be

where edate between trunc(sysdate-7) and trunc(sysdate-1) ;

Upvotes: 2

Related Questions