When it comes to working with dates and times in Oracle, there are various formats you can use to display the data. One of these formats is military time, also known as the 24-hour clock. This format is widely used in the military and other industries that require precise timekeeping. In this article, we will explore how to display datetime in military time in Oracle.
First, let's understand what military time is. In the 24-hour clock, the day is divided into 24 hours, starting at midnight (00:00) and ending at 23:59. Unlike the 12-hour clock, there is no need for AM or PM indicators. Military time is beneficial as it eliminates confusion between morning and evening hours and allows for easier conversion between time zones.
Now, let's see how we can display datetime in military time in Oracle. The most common way to do this is by using the TO_CHAR function. This function converts a datetime value into a specified format. In our case, we will use the 'HH24:MI' format, which represents hours and minutes in the 24-hour clock.
For example, if we have a table named 'orders' with a column 'order_date' that stores the date and time of each order, we can use the following query to display the order date in military time:
SELECT TO_CHAR(order_date, 'HH24:MI') AS military_time
FROM orders;
This will return a result set like this:
MILITARY_TIME
-------------
10:12
16:45
21:30
You can also use the TO_CHAR function with the SYSDATE function to display the current datetime in military time:
SELECT TO_CHAR(SYSDATE, 'HH24:MI') AS current_time
FROM dual;
This will give you the current time in the 24-hour clock format, for example:
CURRENT_TIME
-------------
14:23
In addition to the 'HH24:MI' format, there are other variations you can use to display the datetime in military time. Here are a few examples:
- 'HH24' - This will only display the hour in the 24-hour clock, without the minutes.
- 'HH24:MI:SS' - This will display the hours, minutes, and seconds in the 24-hour clock.
- 'HH24:MI:SS.FF' - This will display the hours, minutes, seconds, and fractional seconds in the 24-hour clock.
You can also use the TO_CHAR function to display the date and time in military time. For that, you will need to specify the 'DD-MM-YYYY HH24:MI' format, which will give you the date and time in the format like this: '10-01-2020 15:05'.
In some cases, you may need to change the time zone before displaying the datetime in military time. For that, you can use the 'AT TIME ZONE' clause in your query. For example, if you want to convert the datetime from the Eastern time zone to the Pacific time zone, you can use the following query:
SELECT TO_CHAR(order_date AT TIME ZONE 'US/Eastern', 'HH24:MI') AS pacific_time
FROM orders;
This will give you the datetime in the Pacific time zone in the 24-hour clock format.
In conclusion, displaying datetime in military time in Oracle is a simple task that can be achieved by using the TO_CHAR function with the appropriate format. Whether you need to display just the time or the date and time in military time, Oracle provides various options to meet your needs. So next time you need to work with military time in your Oracle database, you know exactly how to do it.
