In Oracle Database, the SYS_GUID() function generates and returns a globally unique identifier (RAW value) made up of 16 bytes.
On most platforms, the generated identifier consists of a host identifier, a process or thread identifier of the process or thread invoking the function, and a nonrepeating value (sequence of bytes) for that process or thread.
When using Oracle Database, you can use the TO_CHAR(datetime) function to return various parts of a datetime value, including the fractional seconds.
To return the fractional seconds part from a datetime value, use the FF format element.
In Oracle Database, the NULLIF() function compares two expressions, and returns null if both expressions are equal. If they are not equal, then the function returns the first expression.
In Oracle Database, the NVL() function allows us to replace null values with another value.
In Oracle Database, the COALESCE() function returns the first non-null expression the expression list.
When using the TO_CHAR() function to format a datetime value in Oracle Database, you can add the AD/BC indicator by simply adding either AD or BC to your format model.
Oracle then displays the appropriate indicator, depending on whether the date value is AD or BC.
You can provide it in any uppercase or lowercase, and with or without dots (e.g. AD, A.D. ad, a.d, etc). Oracle will then display the indicator as specified.
Below are two functions that can be used to return the seconds portion from a datetime value in Oracle Database.
This article contains common examples of formatting dates in Oracle Database.
Oracle Database provides the SSSSS format element that enables us to get the number of seconds past midnight from a given datetime value.