how to find out duplicate in a table using sql code example

Example 1: sql query to find duplicates in column

SELECT name, COUNT(email) 
FROM users
GROUP BY email
HAVING COUNT(email) > 1

Example 2: get duplicate records in sql

Multiple field=
SELECT username, email, COUNT(*)
FROM users
GROUP BY username, email
HAVING COUNT(*) > 1

Single field=
SELECT _column, COUNT(*) 
FROM _table
GROUP BY _column
HAVING COUNT(*) > 1