UNIRE DUE QUERY (SENZA UNION)

if exists(select * from sysobjects where id = object_id('Tabella1'))
drop table Tabella1

if exists(select * from sysobjects where id = object_id('Tabella2'))
drop table Tabella2

-- creo e popolo le tabelle
create table Tabella1
(
CODICE    int,
VALORE1   int,
VALORE2  int
)

insert into Tabella1 values (12,100,200)
insert into Tabella1 values (17,87,56)
insert into Tabella1 values (21,178,167)

create table Tabella2
(
CODICE    int,
VALORE1   int,
VALORE2  int
)

insert into Tabella2 values (12,103,230)
insert into Tabella2 values (17,82,55)
insert into Tabella2 values (19,12,45)

-- eseguo la query in full outer join
select *
from Tabella1 a
full outer join Tabella2 b
on a.codice = b.codice

USE tempdb;
GO

CREATE TABLE dbo.Tabella1(
Codice tinyint NOT NULL PRIMARY KEY,
Valore1 tinyint NOT NULL,
Valore2 tinyint NOT NULL
);
GO

CREATE TABLE dbo.Tabella2(
Codice tinyint NOT NULL PRIMARY KEY,
Valore1 tinyint NOT NULL,
Valore2 tinyint NOT NULL
);
GO

INSERT dbo.Tabella1 VALUES(12, 100, 200);
INSERT dbo.Tabella1 VALUES(17, 87, 56);
INSERT dbo.Tabella1 VALUES(21, 178, 167);

INSERT dbo.Tabella2 VALUES(12, 103, 230);
INSERT dbo.Tabella2 VALUES(17, 82, 55);
INSERT dbo.Tabella2 VALUES(19, 12, 45);
GO

SELECT
      COALESCE(T1.Codice, T2.Codice) AS Codice
    , T1.Valore1
    , T1.Valore2
    , T2.Valore1
    , T2.Valore2
FROM dbo.Tabella1 AS T1
FULL JOIN dbo.Tabella2 AS T2
ON T1.Codice = T2.Codice;
GO

/* Output:

Codice Valore1 Valore2 Valore1 Valore2
------ ------- ------- ------- -------
12     100     200     103     230
17     87      56      82      55
19     NULL    NULL    12      45
21     178     167     NULL    NULL

(4 row(s) affected)

*/

DROP TABLE dbo.Tabella1, dbo.Tabella2;