MySQL - Rows to columns with strings -

i've read answer here, mysql - rows columns, , i've been able apply situation until aggregate function (step 3).

i'm trying convert rows in itemname columns rows in itemvalue in following table:

+--------+----------+-----------+ | hostid | itemname | itemvalue | +--------+----------+-----------+ |      1 | address  | 12 street | |      2 | email    | so@gmail  | |      3 | name     | legend    | +--------+----------+-----------+ 

i applied following code:

create view table_extended (   select     history.*,     case when itemname = "address" itemvalue end address,     case when itemname = "email" itemvalue end email,     case when itemname = "name" itemvalue end name   history ); 

and have table_extended:

+--------+----------+-----------+-------------+----------+---------+ | hostid | itemname | itemvalue | address     | email    | name    | +--------+----------+-----------+-------------+----------+---------+ |      1 | address  | 12 street |   12 street | null     | null    | |      1 | email    | so@gmail  |        null | so@gmail | null    | |      1 | name     | legend    |        null | null     | legend  | +--------+----------+-----------+------+------+----------+---------+ 

in step 3 uses sum aggregate extended table of values integers. tried creating view, following code, of course these strings turned of rows except hostid 0.

create view history_itemvalue_pivot (   select     hostid,     sum(address) address,     sum(email) email,     sum(name) name   history_extended   group hostid ); 

it looked this:

+--------+-------------+----------+---------+ | hostid | address     | email    | name    | +--------+-------------+----------+---------+ |      1 | 0           | 0        | 0       | +--------+----------+-----------+------+----+ 

how can consolidate of rows null in order following:

+--------+-------------+----------+---------+ | hostid | address     | email    | name    | +--------+----------+-----------+-----------+ |      1 | 12 street   | so@gmail | legend  | +--------+----------+-----------+------+----+