資料表：每個資料庫的核心

SQL 關聯式資料庫入門

Timo Grossenbacher

Data Journalist

university_professors 資料表的重複資料

SELECT *
FROM university_professors
LIMIT 3;

-[ RECORD 1 ]--------+-------------------------------------------------
firstname            | Karl
lastname             | Aberer
university           | ETH Lausanne
university_shortname | EPF
university_city      | Lausanne
function             | Chairman of L3S Advisory Board
organization         | L3S Advisory Board
organization_sector  | Education & research
-[ RECORD 2 ]--------+-------------------------------------------------
firstname            | Karl
lastname             | Aberer
university           | ETH Lausanne
university_shortname | EPF
university_city      | Lausanne
function             | Member Conseil of Zeno-Karl Schindler Foundation
organization         | Zeno-Karl Schindler Foundation
organization_sector  | Education & research
-[ RECORD 3 ]--------+-------------------------------------------------
firstname            | Karl
lastname             | Aberer
(truncated)
function             | Member of Conseil Fondation IDIAP
organization         | Fondation IDIAP
(truncated)

目前：資料庫中只有一種「實體類型」

更好的資料庫模型：三種實體類型

舊版：

新版：

更好的資料庫模型：四種實體類型

用 CREATE TABLE 建立新資料表

CREATE TABLE table_name (
 column_a data_type,
 column_b data_type,
 column_c data_type
);

用 CREATE TABLE 建立新資料表

CREATE TABLE weather (
 clouds text,
 temperature numeric,
 weather_station char(5)
);

一起來練習吧！

SQL 關聯式資料庫入門