What is the usage of sysdate in Oracle?

In Oracle database, SYSDATE is a function used to return the current system date and time. It can be used directly without any parameters. For example:

SELECT SYSDATE FROM DUAL;

This will return a result containing the current system date and time. The SYSDATE function can be used to compare dates and times. For example:

SELECT * FROM employees WHERE hire_date > SYSDATE-365;

This will return all records from the employee table that have an employment date later than one year ago. The SYSDATE function can be used with other date functions to perform date calculations. For example:

SELECT SYSDATE - hire_date AS working_days FROM employees;

This will return the number of working days for each employee, which is the number of days from their hire date to the current date. Summary: The SYSDATE function is a commonly used date and time function in Oracle, used to retrieve the current system date and time, and can be used in conjunction with other date functions to perform various date calculations and comparisons.