Oracle DB select between dates - sql

Question

I would like to query number of records between night 12.01 AM to 11.59 PM but issue is, I would like to schedule this query so I cant specify any hard coded dates.
Query should pull number of records for query date between 12.01 AM to 11.59 PM.
Could someone please help me on this.

Answer 1

Query should pull number of records for query date between 12.01 AM to 11.59 PM.
You could do it as:
TRUNC gives you date element truncating the time portion
convert the SYSDATE into string using TO_CHAR
then concatenate the time element
finally convert everything back to DATE
SYSDATE returns the current date and time set for the operating system on which the database resides. The datatype of the returned value is DATE, and the format returned depends on the value of the NLS_DATE_FORMAT initialization parameter.
So, you don't have to hard-code any DATE value if you want to execute the query everyday.
Use the following in the filter predicate:
BETWEEN
TO_DATE(TO_CHAR(TRUNC(SYSDATE), 'MM/DD/YYYY') ||' 00:01', 'MM/DD/YYYY HH24:MI')
AND
TO_DATE(TO_CHAR(TRUNC(SYSDATE), 'MM/DD/YYYY') ||' 23:59', 'MM/DD/YYYY HH24:MI')
Demo
SQL> alter session set nls_date_format = 'MM/DD/YYYY HH24:MI:SS';
Session altered.
SQL> SELECT to_date(TO_CHAR(TRUNC(SYSDATE), 'MM/DD/YYYY')
2 ||' 00:01', 'MM/DD/YYYY HH24:MI') start_dt ,
3 to_date(TO_CHAR(TRUNC(SYSDATE), 'MM/DD/YYYY')
4 ||' 23:59', 'MM/DD/YYYY HH24:MI') end_date
5 FROM dual;
START_DT END_DATE
------------------- -------------------
05/06/2015 00:01:00 05/06/2015 23:59:00
SQL>
So, you don't have to put any hard-coded value for current date, the SYSDATE will take care of it. All you are doing is:
TRUNC gives the date element by truncating the time portion.
Then concatenating the required time element
Converting the entire string into DATE using TO_DATE
I would like to schedule this query so I cant specify any hardcord dates
To schedule the query to execute everyday, you could use DBMS_SCHEDULER.

Answer 2

I'm going to assume you want everything that happens during the date of interest. So you want everything from and including midnight of that day and before midnight of the next day.
declare
AsOf Date = date '2015-01-01 13:14:15';
select ...
from tablename
where tabledate >= trunc( AsOf )
and tabledate < trunc( AsOf ) + 1;
If you know the date doesn't have a time portion, just can eliminate the calls to trunc. But you may want to keep them just in case.