Convert from an EAV table in SQL

Question

Im having issues converting to format of an EAV table to something useful. The link table is confusing me and I dont really know how to start fixing this. Anyone have suggestions?

Contacts table

con_id Name Data
1      email [email protected]
2      phone 123
3      email [email protected]
4      phone 456

Link table (maps actual user accounts to rows in the Contacts table):

acct_id con_id
1       1
1       2
2       3
2       4

END GOAL:

acct_id Email       Phone
1       [email protected] 123
2       [email protected] 456

Answer 1

http://sqlfiddle.com/#!4/7cf20/5/0

CREATE TABLE Contacts
    (con_id int, Name varchar2(5), Data varchar2(11))
;

INSERT ALL 
    INTO Contacts (con_id, Name, Data)
         VALUES (1, 'email', '[email protected]')
    INTO Contacts (con_id, Name, Data)
         VALUES (2, 'phone', '123')
    INTO Contacts (con_id, Name, Data)
         VALUES (3, 'email', '[email protected]')
    INTO Contacts (con_id, Name, Data)
         VALUES (4, 'phone', '456')
SELECT * FROM dual
;

CREATE TABLE Link
    (acct_id int, con_id int)
;

INSERT ALL 
    INTO Link (acct_id, con_id)
         VALUES (1, 1)
    INTO Link (acct_id, con_id)
         VALUES (1, 2)
    INTO Link (acct_id, con_id)
         VALUES (2, 3)
    INTO Link (acct_id, con_id)
         VALUES (2, 4)
SELECT * FROM dual
;

Query -

select * from (
select acct_id, name, Data
from contacts c, Link l
where c.con_id = l.con_id
)
pivot (max(Data) for name in ('email' as Email,'phone' as Phone));

Output -

ACCT_ID EMAIL         PHONE
1       [email protected]   123
2       [email protected]   456