find duplicate column values in sql code example

Example 1: select duplicates in sql

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

Example 2: sql query to find duplicates in column

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

Example 3: select where duplicate mysql

SELECT 
    col1, COUNT(col1),
    col2, COUNT(col2)
FROM
    table_name
GROUP BY 
    col1, 
    col2
HAVING 
       (COUNT(col1) > 1) AND 
       (COUNT(col2) > 1);