SYSDATE()
Returns the current date and time as a value in either YYY-MM-DD
HH:MM:SS or YYYMMDDHHMMSS format, depending on whether the function is
used in a string or numeric context. The function NOW works in a similar manner, except that
it returns the time and date only at the start of the current
statement, whereas SYSDATE returns
the time and date at the exact moment the function itself is called.
On December 19, 2016, this code will return the values 2016-12-19 19:11:13 and 20161219191113:
SELECT SYSDATE(); SELECT SYSDATE() + 0;