Oracle领导职能

Posted 2021-02-22

A few examples of the LEAD function.

SELECT * FROM student;
 
--Example 1
SELECT student_id, first_name, last_name, enrolment_date,
LEAD(enrolment_date) OVER (ORDER BY enrolment_date ASC) AS next_enr_date
FROM student
ORDER BY student_id ASC;
 
--Example 2
SELECT student_id, first_name, last_name, enrolment_date,
LEAD(enrolment_date) OVER (ORDER BY enrolment_date ASC) AS next_enr_date
FROM student
ORDER BY enrolment_date ASC;
 
--Example 3
SELECT student_id, first_name, last_name, enrolment_date,
LEAD(enrolment_date, 2, '31-DEC-2999') OVER (ORDER BY enrolment_date ASC) AS next_enr_date
FROM student
ORDER BY enrolment_date ASC;
 
 
--Example 3
SELECT student_id, first_name, last_name, enrolment_date,
LEAD(enrolment_date) OVER (ORDER BY enrolment_date ASC) AS next_enr_date
FROM student
WHERE LEAD(enrolment_date) OVER (ORDER BY enrolment_date ASC) > '01-FEB-2015'
ORDER BY enrolment_date ASC;