How to convert decimal to time in Oracle SQL? - sql

Question

In a certain table I'm querying, time is stored like this:
09:30 is stored as 9,3
14:25 is stored as 14,25
How can I, using SQL, convert 9,3 to 09:30 (hh:mm format)?
So far, the only thing I could find in other questions are people who need to convert 9,5 to 09:30 (in my case, 9,5 means 09:50).
Right now, I'm using PHP to convert this. But my DB server is better than my application server. Since I need to get a lot of data, it would be better to solve this using SQL.
Sorry if this is a stupid question, but I'm new to SQL. Feel free to ask for more questions if you need to.

Answer 1

Assuming those are numeric values, you can get the hour part with trunc(your_column) and the minutes part with 100 * mod(your_column, 1). That gives you two numbers; you can format those and concatenate them, again assuming you want a string result, e.g.:
to_char(trunc(your_column), 'FM00') ||':' || to_char(100 * mod(your_column, 1), 'FM00')
Or more simply, format the whole number as a single string in one step, by telling it to use a colon as the decimal separator (with anything as the group separator - that isn't used):
to_char(your_column, 'FM00D00', 'NLS_NUMERIC_CHARACTERS=:,')
Demo with sample data in a CTE:
-- CTE for sample data
with your_table (time) as (
select 9.3 from dual
union all select 9.03 from dual
union all select 14.25 from dual
)
-- actual query
select time,
to_char(trunc(time), 'FM00') ||':' || to_char(100 * mod(time, 1), 'FM00') as new_time1,
to_char(time, 'FM00D00', 'NLS_NUMERIC_CHARACTERS=:,') as new_time2
from your_table;
TIME NEW_TIME1 NEW_TIME2
---------- --------- ---------
9.3 09:30 09:30
9.03 09:03 09:03
14.25 14:25 14:25
If you actually want an interval data type result then you can use the same split with trunc/mod but handle the two numbers differently:
select time,
numtodsinterval(trunc(time), 'HOUR')
+ numtodsinterval(100 * mod(time, 1), 'MINUTE') as new_time
from your_table;
TIME NEW_TIME
---------- -------------------
9.3 +00 09:30:00.000000
9.03 +00 09:03:00.000000
14.25 +00 14:25:00.000000
Or you can convert to that time on a nominal date if you prefer, e.g.:
date '2000-01-01'
+ trunc(your_column), 'HOUR')
+ numtodsinterval(100 * mod(your_column, 1), 'MINUTE')
At some point you'll run into problems if you have values that don't really represent valid times - for example, 9.60 or 25.3. Either of the queries above will handle that to some extent - at least, up to 99.99 for the first one - but won't necessarily give useful results. The string would give you '09:60' and '25:30', while the interval would give you '0 10:00:00' and '1 01:30:00', which is slightly more sensible perhaps. That's the danger of using an inappropriate data type though.
Preserving a comment from #BobJarvis, if you actually want a date data type result then you can convert the number to a string without any separator and then convert from that to a date:
to_date(to_char(your_column, '00V00'), 'HH24MI')
which will give you that time on the first day of the current month. However, that will error with 9.60 or 25.3.