First of all what are Built-in functions?
These are functions which do not need any sort of arguments but still returns information about the system; user, date, time, session etc. Built-in functions are sometimes referred to as special registers. Mostly used with the SELECT statement.
SELECT <Built-In Function>
• ACCOUNT: – If you are wondering about your Teradata Account information just use this function to see your current account string.
• CURRENT_DATE: – Returns the current system date and it is same as the function DATE.
• CURRENT_TIME: – This function returns the current system time and current session ‘Time Zone’ displacement. This function is similar to the TIME function but with extra feature of Time Zone displacement.
• CURRENT_TIMESTAMP: – Returns the current system timestamp (including year, month and day) and current session Time Zone displacement.
• DATABASE: – If you are wondering how to find your current database name, use this function which returns the name of the default database for the current user.
• DATE: – As mentioned earlier, it does return the current date.
• SESSION: – Returns a number for the session the current user is in. Two sessions does not have the same number. If you want to identify your session, this is the function to use.
• TIME: – As mentioned, this function provides the current time based on a 24-hour day; mean to say for 4:00 pm, you would see 16:00:00.
• USER: – If you have forgotten your username after you have logged in, this command would come to your rescue. This one gives the user name of the current user.