How to identify duplicate value in mysql?

@denis 

To identify duplicate values in MySQL, you can use the following steps:

1. Use the GROUP BY clause with the COUNT() aggregate function to group the data by the column you suspect contains duplicate values. Example: SELECT column_name, COUNT(column_name) FROM table_name GROUP BY column_name
2. Add a HAVING clause with the COUNT() function to filter the groups to only show those with a count greater than 1. Example: SELECT column_name, COUNT(column_name) FROM table_name GROUP BY column_name HAVING COUNT(column_name) > 1
3. Run the query, and the result will display the duplicate values and the count of their occurrence in the specified column.

This method will allow you to identify the duplicate values in the MySQL database based on a specific column.