Database Management Systems
In MariaDB, the SYSDATE() and NOW() functions are similar in that they return the current date and time.
However, there is an important difference: SYSDATE() returns the time that it executes, whereas NOW() returns the time that the statement started executing.
And when run within a stored procedure or trigger, SYSDATE() will return the time that it executes, whereas NOW() will return the time that the stored procedure or trigger started executing.
In Oracle Database, we can use the TO_CHAR(datetime) function to return the various date parts from a datetime value, including the short month name.
The short month name is also referred to as the abbreviated month name. Examples of returning the short month name are below.
In Oracle Database, the UID function returns an integer that uniquely identifies the session user (the user who logged on).
If you’re using SQLcl to run queries against Oracle Database, then you can use the SPOOL command to export your query results to a CSV file.
In Oracle Database, the USER function returns the name of the session user (the user who logged on).
MariaDB has several functions that enable you to extract various date and time parts from date/time values. You can use these to separate each date/time component into its own column if required.
Below are four ways to extract the hours, minutes, and seconds from a time value in MariaDB. As a bonus, we’ll also include microseconds.
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.