SQL Random Queries

Finding duplicate values in a SQL table

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

SELECT

name, email, COUNT(*)

FROM

users

GROUP BY

name, email

HAVING

COUNT(*) > 1

MySQL Update Column from other column in same table

UPDATE
   bjp_users 
   JOIN
      bjp_mla 
      ON bjp_mla.constituency = bjp_users.username 
SET
   bjp_users.c_no = bjp_mla.c_no

UPDATE

bjp_users

JOIN

bjp_mla

ON bjp_mla.constituency = bjp_users.username

SET

bjp_users.c_no = bjp_mla.c_no

My-SQL