hUZ6T

DB2デザイン・ガイド
解説
�UNION ALLビューの例
CREATE TABLE Q1(order DATE,month SMALLINT,item VARCHAR(10));
ALTER TABLE Q1 ADD CONSTRAINT q1ckc1 CHECK (MONTH BETWEEN 1 AND 3);
ORDER MONT ITEM
2003-01-01 H
2003-02-01
1 xxxx
2 xxxx
表Q1
2003-03-01 3 xxxx
CREATE TABLE Q2(order DATE, month SMALLINT,item VARCHAR(10));
ALTER TABLE Q2 ADD CONSTRAINT q2ckc1 CHECK (MONTH BETWEEN 4 AND 6);
ORDER MONT ITEM
2003-04-01 H 4 xxxx
2003-05-01 5 xxxx
2003-06-01 6 xxxx
表Q2
CREATE TABLE Q3(order DATE, month SMALLINT,item VARCHAR(10));
ALTER TABLE Q3 ADD CONSTRAINT q3ckc1 CHECK (MONTH BETWEEN 7 AND 9);
ORDER MONT ITEM
2003-07-01 H
2003-08-01
7 xxxx
8 xxxx
表Q3
2003-09-01 9 xxxx
CREATE TABLE Q4(order DATE, month SMALLINT,item VARCHAR(10));
ALTER TABLE Q4 ADD CONSTRAINT q4ckc1 CHECK (MONTH BETWEEN 10 AND 12);
ORDER MONT ITEM
2003-10-01 H
2003-11-01
10 xxxx
11 xxxx
表Q4
2003-12-01 12 xxxx
©日本IBMｼｽﾃﾑｽﾞ･ｴﾝｼﾞﾆｱﾘﾝｸﾞ(株) Information Management部
36
データベース物理設計
CREATE VIEW VIEW_YEAR(order,
month,item) AS SELECT * FROM Q1
UNION ALL
SELECT * FROM Q2
UNION ALL
SELECT * FROM Q3
UNION ALL
SELECT * FROM Q4;
ビュー
VIEW_YEAR
ORDER MONTH ITEM
2003-01-01 1 xxxx
2003-02-01 2 xxxx
2003-03-01 3 xxxx
2003-04-01 4 xxxx
2003-05-01 5 xxxx
2003-06-01 6 xxxx
2003-07-01 7 xxxx
2003-08-01 8 xxxx
2003-09-01 9 xxxx
2003-10-01 10 xxxx
2003-11-01 11 xxxx
2003-12-01 12 xxxx