How to delete the duplicate values stored in reverse order from MySQL table?
To understand this concept, we are using the data from table ‘Details_city’ as follows −
mysql> Select * from details_city;
+--------+--------+
| City1 | City2 |
+--------+--------+
| Delhi | Nagpur |
| Delhi | Mumbai |
| Nagpur | Delhi |
| Katak | Delhi |
| Delhi | Katak |
+--------+--------+
5 rows in set (0.00 sec)
Now, the following query will delete the reverse duplicate values from details_city table −
mysql> Select a.city1,a.city2 from details_city a WHERE a.city1 <= a.city2;
+-------+--------+
| city1 | city2 |
+-------+--------+
| Delhi | Nagpur |
| Delhi | Mumbai |
| Delhi | Katak |
+-------+--------+
3 rows in set (0.06 sec)
Published on 22-Feb-2018 08:09:38
