以mysql自帶的world數(shù)據(jù)庫為例說明以下最常用

world結(jié)構(gòu)

city結(jié)構(gòu)

SELECT

選取

SELECT id,name 
FROM WORLD.CITY

WHERE

條件

SELECT id,name,population
FROM WORLD.CITY
WHERE Population >= 600000

AND&OR

SELECT *
FROM WORLD.CITY
WHERE Population >= 600000 and countrycode = 'AUS';
SELECT *
FROM WORLD.CITY
WHERE Population >= 600000 or countrycode = 'AUS';

and&or

ORDER BY

可以針對(duì)數(shù)字排序 ，也可以對(duì)文本排序，甚至可以針對(duì)多個(gè)條件排序（以逗號(hào),分隔）

SELECT *
FROM WORLD.CITY
WHERE Population >= 600000
ORDER BY population

以population從低到高排序
由高到低排序?yàn)?/p>

ORDER BY population desc

INSERT

插入

INSERT INTO world.city VALUES (19989,'test','AFG','kabol','100000');
INSERT INTO world.city (ID,NAME,COUNTRYCODE) VALUES (19899,'test','AFG')

UPDATE

UPDATE world.city SET id = 19898 WHERE id = 19899

DELETE

DELETE FROM world.city WHERE id = 19899