Check if a specific field in MySQL has duplicates.

You can use the GROUP BY and HAVING clauses to check if a certain field has duplicate values.

For example, if there is a table named “table_name” with a column named “column_name”, and we want to check if this column has any duplicate values, we can use the following SQL query:

SELECT column_name, COUNT(column_name)
FROM table_name
GROUP BY column_name
HAVING COUNT(column_name) > 1;

This query will return all fields with repeated values and their occurrence count. If there are no repeated values, the query result will be empty.