Question

Let’s have a query

SELECT `name`, `companyid`
  FROM `users`

where the result could be

Peter   | 1
Michael | 1
Tom     | 2
John    | 2
Ian     | 4

Is it possible to create a query result where for each unique companyid value would be added a row

System  | <current companyId>

so the result would be

Peter   | 1
Michael | 1
System  | 1
Tom     | 2
John    | 2
System  | 2
Ian     | 4
System  | 4

Answer 1

SELECT * FROM
( 
  SELECT name,companyid FROM users
  UNION ALL
  SELECT DISTINCT 'System', companyid FROM users
)
ORDER BY companyid