O que há de diferente entre INTERSECT e JOIN?
Ajude-me, por favor.
Crie dados:
CREATE TABLE sub1(id int,name nvarchar(7));
CREATE TABLE sub2(id int,name nvarchar(7));
INSERT INTO sub1 VALUES(1,'one1');
INSERT INTO sub2 VALUES(1,'one1');
INSERT INTO sub1 VALUES(2,'one2');
INSERT INTO sub2 VALUES(2,'one2');
INSERT INTO sub1 VALUES(3,'one3');
INSERT INTO sub2 VALUES(4,'one4');
INSERT INTO sub1 VALUES(5,'one5');
INSERT INTO sub2 VALUES(6,'one6');
INSERT INTO sub1 VALUES(NULL,NULL);
INSERT INTO sub2 VALUES(NULL,NULL);
O que há de diferente entre duas consultas:
SELECT * FROM sub1 INTERSECT SELECT * FROM sub2
SELECT sub1.id,sub1.name FROM sub1 JOIN sub2 ON sub1.id = sub2.id
O que há de diferente entre INTERSECT e JOIN?