Sybase Adaptive Server Anywhere - Page 494

CREATE TABLE statement
476
CREATE TABLE library_books (
-- NOT NULL is assumed for primary key columns
isbn CHAR(20) PRIMARY KEY,
copyright_date DATE,
title CHAR(100),
author CHAR(50),
-- column(s) corresponding to primary key of room
-- are created automatically
FOREIGN KEY location REFERENCES room
)
♦ Create a table for a library database to hold information on borrowed
books.
CREATE TABLE borrowed_book (
-- Default on insert is that book is borrowed today
-- date_borrowed DATE NOT NULL DEFAULT CURRENT DATE,
-- date_returned will be NULL until the book is
-- returned
date_returned DATE,
book CHAR(20)
REFERENCES library_books (isbn),
-- The check condition is UNKNOWN until
-- the book is returned, which is allowed
CHECK( date_returned >= date_borrowed )
)
♦ Create tables for a sales database to hold order and order item
information.
CREATE TABLE Orders (
order_num INTEGER NOT NULL PRIMARY KEY,
date_ordered DATE,
name CHAR(80)
);
CREATE TABLE Order_item (
order_num INTEGER NOT NULL,
item_num SMALLINT NOT NULL,
PRIMARY KEY (order_num, item_num),
-- When an order is deleted, delete all of its
-- items.
FOREIGN KEY (order_num)
REFERENCES Orders (order_num)
ON DELETE CASCADE
)
♦ Creates a table named t1 at the remote server SERVER_A and creates a
proxy table named
t1 that is mapped to the remote table.
CREATE TABLE t1
( a INT,
b CHAR(10))
AT ’SERVER_A.db1.joe.t1’