Salut,

Am urmatoarea intrebare. Pot in SQL Server sa aplic operatorul diferenta intre doua seturi de date? Daca da, cum?

 

Multumesc,

EXCEPT and INTERSECT (Transact-SQL)

Performing Semi-Joins with EXCEPT and INTERSECT

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Cristian Andrei Lefter, SQL Server MVP
MCT, MCSA, MCDBA, MCAD, MCSD .NET,
MCTS, MCITP - Database Administrator SQL Server 2005
http://sqlserver.ro

Poti face diferenta cu un simplu LEFT | RIGHT OUTER JOIN.

Exemplu:

CREATE TABLE T1 (C1 CHAR(1), C2 INT)
CREATE TABLE T2 (C1 CHAR(1), C2 INT)

INSERT INTO T1 (C1, C2)
SELECT Q.C1, Q.C2
FROM
(
SELECT 'A' AS C1, 101 AS C2
UNION
SELECT 'B', 102
UNION
SELECT 'C', 103
UNION
SELECT 'D', 104
UNION
SELECT 'E', 105
) AS Q

INSERT INTO T2 (C1, C2)
SELECT Q.C1, Q.C2
FROM
(
SELECT 'A' AS C1, 101 AS C2
UNION
SELECT 'B', 102
UNION
SELECT 'X', 106
) AS Q

--DIFERENTA PROPRIU-ZISA; T1-T2 = INREGISTRARILE DIN T1 CARE NU SUNT IN T2
SELECT T1.C1, T1.C2
FROM T1 LEFT OUTER JOIN T2 ON T1.C1 = T2.C1 AND T1.C2 = T2.C2
WHERE T2.C1 IS NULL
 

Sau subinterogari tip NOT EXISTS:

SELECT *
FROM T1
WHERE NOT EXISTS(SELECT C1 FROM T2 WHERE T1.C1 = T2.C1 AND T1.C2 = T2.C2)