Reverse pair duplicate data" in SQL typically refers to a situation where you have pairs of records in a database where the order of the elements in each pair is reversed but the content is identical or corresponds in some meaningful way.

For example, if you have a database that stores relationships between people, you might have pairs of records like this:
  • Person A is related to Person B
  • Person B is related to Person A
In this case, both pairs represent the same relationship, but the order in which the people are listed is reversed. This can lead to data redundancy and inconsistencies if not managed properly.

Detecting and managing reverse pair duplicate data often involves writing SQL queries to identify and clean up such records to ensure data consistency and eliminate redundancy in the database.

This video demonstrates how to address duplicate reverse pair data in SQL.

Table schema:

CREATE TABLE src_dest(
source VARCHAR50),
destination VARCHAR(50),
distance INT
)

INSERT INTO src_dest(source,destination,distance)
VALUES('Alaska','Albany',5166),
('Dover','Florida',1393),
('Illinois','Indiana',279),
('New Mexico','New York',2873),
('Albany','Alaska',5166),
('Ohio','Oklahoma',1383),
('Indiana','Illinois',279),
('Oklahoma','Ohio',1383),
('Frankfort','Georgia',695),
('Georgia','Frankfort',695)