定義資料庫架構
評估並改善實體模型後,您就可以在 CQL 中實作架構。以下是 hotel
鍵集空間的架構,使用 CQL 的註解功能來記錄每個表格支援的查詢模式
CREATE KEYSPACE hotel WITH replication =
{'class': 'SimpleStrategy', 'replication_factor' : 3};
CREATE TYPE hotel.address (
street text,
city text,
state_or_province text,
postal_code text,
country text );
CREATE TABLE hotel.hotels_by_poi (
poi_name text,
hotel_id text,
name text,
phone text,
address frozen<address>,
PRIMARY KEY ((poi_name), hotel_id) )
WITH comment = 'Q1. Find hotels near given poi'
AND CLUSTERING ORDER BY (hotel_id ASC) ;
CREATE TABLE hotel.hotels (
id text PRIMARY KEY,
name text,
phone text,
address frozen<address>,
pois set<text> )
WITH comment = 'Q2. Find information about a hotel';
CREATE TABLE hotel.pois_by_hotel (
poi_name text,
hotel_id text,
description text,
PRIMARY KEY ((hotel_id), poi_name) )
WITH comment = Q3. Find pois near a hotel';
CREATE TABLE hotel.available_rooms_by_hotel_date (
hotel_id text,
date date,
room_number smallint,
is_available boolean,
PRIMARY KEY ((hotel_id), date, room_number) )
WITH comment = 'Q4. Find available rooms by hotel date';
CREATE TABLE hotel.amenities_by_room (
hotel_id text,
room_number smallint,
amenity_name text,
description text,
PRIMARY KEY ((hotel_id, room_number), amenity_name) )
WITH comment = 'Q5. Find amenities for a room';
請注意,即使分割鍵只包含單一欄位 poi_name
,分割鍵的元素仍以括號括起來。這是最佳做法,可以讓讀取 CQL 的其他人更清楚地了解分割鍵的選擇。
類似地,以下是 reservation
鍵集空間的架構
CREATE KEYSPACE reservation WITH replication = {'class':
'SimpleStrategy', 'replication_factor' : 3};
CREATE TYPE reservation.address (
street text,
city text,
state_or_province text,
postal_code text,
country text );
CREATE TABLE reservation.reservations_by_confirmation (
confirm_number text,
hotel_id text,
start_date date,
end_date date,
room_number smallint,
guest_id uuid,
PRIMARY KEY (confirm_number) )
WITH comment = 'Q6. Find reservations by confirmation number';
CREATE TABLE reservation.reservations_by_hotel_date (
hotel_id text,
start_date date,
end_date date,
room_number smallint,
confirm_number text,
guest_id uuid,
PRIMARY KEY ((hotel_id, start_date), room_number) )
WITH comment = 'Q7. Find reservations by hotel and date';
CREATE TABLE reservation.reservations_by_guest (
guest_last_name text,
hotel_id text,
start_date date,
end_date date,
room_number smallint,
confirm_number text,
guest_id uuid,
PRIMARY KEY ((guest_last_name), hotel_id) )
WITH comment = 'Q8. Find reservations by guest name';
CREATE TABLE reservation.guests (
guest_id uuid PRIMARY KEY,
first_name text,
last_name text,
title text,
emails set,
phone_numbers list,
addresses map<text,
frozen<address>,
confirm_number text )
WITH comment = 'Q9. Find guest by ID';
您現在擁有完整的 Cassandra 架構,可儲存飯店應用程式的資料。
摘錄自《Cassandra, The Definitive Guide》。由 O’Reilly Media, Inc. 出版。版權所有 © 2020 Jeff Carpenter、Eben Hewitt。保留所有權利。經許可使用。