The CURDATE(), CURRENT_DATE, CURRENT_DATE, SYS_DATE, and SYSDATE are used interchangeably, and they return the current date as the DATE type (MM/DD/YYYY or YYYY-MM-DD). The unit is day.
If every argument value of date is 0, the return value is determined by the return_null_on_function_errors system parameter; if it is set to yes, then NULL is returned; if it is set to no, an error is returned. The default value is no.
CURDATE()
CURRENT_DATE()
CURRENT_DATE
SYS_DATE
SYSDATE
--it returns the current date in DATE type
SELECT CURDATE(), CURRENT_DATE(), CURRENT_DATE, SYS_DATE, SYSDATE;
SYS_DATE SYS_DATE SYS_DATE SYS_DATE SYS_DATE
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04/01/2010 04/01/2010 04/01/2010 04/01/2010 04/01/2010
--it returns the date 60 days added to the current date
SELECT CURDATE()+60;
SYS_DATE +60
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05/31/2010
SELECT TO_DAYS('0000-00-00');
ERROR: Conversion error in date format.