Automatically populate a "time_hour" table - sql

Question

I have a requirement to store 24 hours in a day in a table "time_hours". Here is the structure of my table:
Create table time_hours
(HOURS number,
HOUR_RANGE VARCHAR (20),
HOUR_MIN VARCHAR (20),
HOUR_MAX VARCHAR(20));
Here is the script I have so far:
Insert into time_hours(HOURS,
HOUR_RANGE,
HOUR_MIN,
HOUR_MAX)
Select
to_number(to_char(t,'HH24'),'00'),
to_char(t,'HH24:MI:SS'),
to_char(t,'HH24:MI:SS'),
to_char(t,'HH24:MI:SS')
FROM
(
Select trunc(sysdate) + (level-1)/24 as t
FROM dual
Connect by level <=24
);
The results is:
Hours | HOUR_RANGE | HOUR_MIN | HOUR_MAX
0 00:00:00 00:00:00 00:00:00
1 01:00:00 01:00:00 01:00:00
..
23 23:00:00 23:00:00 23:00:00
However I need this output:
Hours | HOUR_RANGE | HOUR_MIN | HOUR_MAX
0 00h-00h59 00:00:00 00:59:59
1 01h00-01h59 01:00:00 01:59:59
2 02h00-02h59 02:00:00 02:59:59
.. .. .. ..
23 23h00-23h59 23:00:00 23.59.59
My Question:
How can I format the "HOUR_RANGE" and "HOUR_MAX" columns to give me the expected output?
Thank you all in advance for your help

Answer 1

You could use:
Select
to_number(to_char(t,'HH24'),'00') AS Hours,
to_char(t,'HH24"h"MI"-"HH24"h59"') AS HOUR_RANGE,
to_char(t,'HH24:MI:SS') AS HOUR_MIN,
to_char(t+1/24-1/(24*3600),'HH24:MI:SS') AS HOUR_MAX
FROM (Select trunc(sysdate) + (level-1)/24 as t
FROM dual
Connect by level <=24 );
Rextester Demo

Answer 2

After all, it's just strings containing the hour plus some other characters. No date conversion needed at all.
insert into time_hours(hours, hour_range, hour_min, hour_max)
select
level-1 as hours,
to_char(level-1, '00') || 'h00-' || to_char(level-1, '00') || 'h59' as hour_range,
to_char(level-1, '00') || ':00:00'as hour_min,
to_char(level-1, '00') || ':59:59'as hour_max
from dual connect by level <= 24;

Answer 3

I think you can use code below.
You can use pipelines to concatenate characters.
You can use some arithmetic operations to get max minutes and seconds of given hour; 1/24*60 = 1/1440 to add a minute to a date value. 1/24*60*60 = 1/86400 to add a second to a date value.
INSERT INTO time_hours (HOURS, HOUR_RANGE, HOUR_MIN, HOUR_MAX)
SELECT
to_number(to_char(t, 'HH24'), '00'),
to_char(t, 'HH24') || 'h' || to_char(t, 'MI') || '-' || to_char(t, 'HH24') || 'h59',
to_char(t, 'HH24:MI:SS'),
to_char(t + 1/86400*59 + 1/1440*59, 'HH24:MI:SS')
FROM (SELECT trunc(SYSDATE) + (LEVEL - 1) / 24 AS t
FROM dual
CONNECT BY LEVEL <= 24);