Je sais que vous ne pouvez pas comparer une valeur à NULL et attendre un résultat sans ajouter quelque chose comme dans le code suivant ...
SELECT
*
FROM
A INNER JOIN
B ON A.ID = B.ID
WHERE
A.STRING <> B.STRING OR (A.STRING IS NULL AND B.STRING IS NOT NULL) OR (A.STRING IS NOT NULL AND B.STRING IS NULL) OR
A.DT <> B.DT OR (A.DT IS NULL AND B.DT IS NOT NULL) OR (A.DT IS NOT NULL AND B.DT IS NULL) OR
A.B <> B.B OR (A.B IS NULL AND B.B IS NOT NULL) OR (A.B IS NOT NULL AND B.B IS NULL) OR
A.NUM <> B.NUM OR (A.NUM IS NULL AND B.NUM IS NOT NULL) OR (A.NUM IS NOT NULL AND B.NUM IS NULL)
Ma question est:
Existe-t-il un moyen plus élégant de tester les valeurs modifiées dans les deux tables où l'une ou l'autre pourrait être nulle?
La solution doit fonctionner uniformément sur tous les types de données.
Voici le code pour configurer les tables de test ...
CREATE TABLE A
(
ID INT IDENTITY(1,1) NOT NULL,
STRING VARCHAR(20) NULL,
DT DATETIME NULL,
B BIT NULL,
NUM INT NULL
)
CREATE TABLE B
(
ID INT IDENTITY(1,1) NOT NULL,
STRING VARCHAR(20) NULL,
DT DATETIME NULL,
B BIT NULL,
NUM INT NULL
)
INSERT INTO A (STRING, DT, B, NUM) VALUES ('TEST', '2012-03-16 16:39:04.893', 0, 23)
INSERT INTO A (STRING, DT, B, NUM) VALUES (NULL, '2012-03-16 16:39:04.893', 0, 23)
INSERT INTO A (STRING, DT, B, NUM) VALUES ('TEST', NULL, 0, 23)
INSERT INTO A (STRING, DT, B, NUM) VALUES ('TEST', '2012-03-16 16:39:04.893', NULL, 23)
INSERT INTO A (STRING, DT, B, NUM) VALUES ('TEST', '2012-03-16 16:39:04.893', 0, NULL)
INSERT INTO A (STRING, DT, B, NUM) VALUES ('TEST', '2012-03-16 16:39:04.893', 0, 23)
INSERT INTO A (STRING, DT, B, NUM) VALUES ('TEST', '2012-03-16 16:39:04.893', 0, 23)
INSERT INTO A (STRING, DT, B, NUM) VALUES ('TEST', '2012-03-16 16:39:04.893', 0, 23)
INSERT INTO A (STRING, DT, B, NUM) VALUES ('TEST', '2012-03-16 16:39:04.893', 0, 23)
INSERT INTO A (STRING, DT, B, NUM) VALUES ('TEST', '2012-03-16 16:39:04.893', 0, 23)
INSERT INTO B (STRING, DT, B, NUM) VALUES ('TEST', '2012-03-16 16:39:04.893', 0, 23)
INSERT INTO B (STRING, DT, B, NUM) VALUES ('TEST', '2012-03-16 16:39:04.893', 0, 23)
INSERT INTO B (STRING, DT, B, NUM) VALUES ('TEST', '2012-03-16 16:39:04.893', 0, 23)
INSERT INTO B (STRING, DT, B, NUM) VALUES ('TEST', '2012-03-16 16:39:04.893', 0, 23)
INSERT INTO B (STRING, DT, B, NUM) VALUES ('TEST', '2012-03-16 16:39:04.893', 0, 23)
INSERT INTO B (STRING, DT, B, NUM) VALUES ('STAGE', '2012-03-16 16:39:04.893', 0, 23)
INSERT INTO B (STRING, DT, B, NUM) VALUES ('TEST', '2555-11-11 00:00:00.000', 0, 23)
INSERT INTO B (STRING, DT, B, NUM) VALUES ('TEST', '2012-03-16 16:39:04.893', 0, 23)
INSERT INTO B (STRING, DT, B, NUM) VALUES ('TEST', '2012-03-16 16:39:04.893', 0, 23)
INSERT INTO B (STRING, DT, B, NUM) VALUES ('TEST', '2012-03-16 16:39:04.893', 0, 999)