Inverse SQL: SELECT column_name WHERE value

Question

Let's assume we have table logins:

id| name  | lastname
---------------------
1 | mark  | johnson
2 | jack  | sparrow
3 | bruno | mark

We all know, that we can query SQL similiar to: SELECT name FROM login WHERE id = 1; and get in return mark .

I am looking for query like:

SELECT column_name FROM logins WHERE value = 'mark';

which will result in name, lastname or even

SELECT column_name FROM logins WHERE value = 'mark' AND id = 1;

which will result in name .

EDIT: The question is more complex than simple answers given. Real problem is how to select column name from 100+ columns, when we know expected value. For example we know that somewhere in table there is value 17,58 , but we want to find column name.

Answer 1

Getting the column name directly is not possible however using the case statement you can construct the query to return the column name for a matched value something as

select
id,
case 
 when name = 'mark' then 'name' 
 when lastname = 'mark' then 'lastname'
 else 'Nothing'
end as column_name 
from logins

DEMO

Answer 2

In PostgreSQL you can use the hstore extension for this (I don't think there is anything remotely similar available in MySQL):

with login_data as (
  select id, 
         skeys(hstore(l)) as column_name,
         svals(hstore(l)) as column_value
  from logins as l
  where avals(hstore(l)) @> array['mark']
) 
select id, column_name
from login_data
where column_value = 'mark'
;

SQLFiddle example: http://sqlfiddle.com/#!15/115d5/1

But the performance will most probably be quite horrible.

Answer 3

如果您想在（名称）或（姓氏）ID中获得名称，则认为这将对您有所帮助

SELECT column_name FROM logins WHERE ( name  = 'mark' Or lastname = 'mark') AND id = 1;

Answer 4

如果您不知道用户ID，则类似以下内容：

SELECT DISTINCT name FROM logins WHERE name = 'mark';