創建用戶表:
CREATE TABLE IF NOT EXISTS user_info
(
userId
INT UNSIGNED AUTO_INCREMENT,
loginName
VARCHAR(20) NOT NULL,
phone
VARCHAR(11) NOT NULL,
name
VARCHAR(40) NOT NULL,
pronvince
VARCHAR(40) NOT NULL,
address
VARCHAR(40) NOT NULL,
sex
INTEGER,
registerData
DATE,
PRIMARY KEY ( userId
)
)ENGINE=InnoDB DEFAULT CHARSET=utf8;
查詢表
SELECT * FROM user_info;
SELECT * FROM user_info WHERE userId=1;
1.插入表數據
INSERT INTO user_info (loginName
,phone
,name
,pronvince
,city
,address
,sex
,registerData
)
VALUES(‘123554’,‘17620185859’,‘cping’,‘廣東’,‘廣州’,‘天河區’,1,‘2018-12-06’);
DELETE FROM user_info WHERE userId=2;
SELECT * FROM user_info;
2.插入表數據
INSERT INTO user_info VALUES(1,‘123554’,‘17620185859’,‘cping’,‘廣東’,‘廣州’,‘天河區’,1,‘2018-12-06’);
兩種語法比較,1,可以不插入自增id,2 必須插入,一一對應
3.更新表數據
UPDATE table_name
SET column1=value1,column2=value2,…
WHERE some_column=some_value;
4.刪除表數據
DELETE FROM user_info WHERE userId=2;
5.排序表數據
SELECT column_name,column_name
FROM table_name
ORDER BY column_name,column_name ASC|DESC;
從小到大( ASC) | 從大到小(|DESC)
6.SQL AND & OR TOP運算符
SELECT * FROM table_name WHERE column_name operator value AND column_name operator value;
SELECT * FROM table_name WHERE column_name operator value OR column_name operator value;
SqlServer/ms access語法:
SELECT TOP 50 PERCENT * FROM table_name; 50%的數據
SELECT TOP 100 column_name * FROM table_name; 前100的數據
MySql語法:
SELECT *FROM table_name LIMIT 100;
7.修改表的字段
alter table user_info change pronvince province varchar(20);
其它修改表的類型:
(1)修改表的名稱呢
alter table 表名 rename to 新的名字;
demo:
alter table ta1 rename to ta0;
(2)添加一個新字段
alter table 表名 add 新字段 字段的類型;
demo:
alter table ta0 add unames varchar(20);
(3)修改字段:
alter table 表名 change 舊得字段 新的字段 字段的數據類型;
alter table ta0 change unames uname varchar(20);
(4)修改字段的類型:
alter table 表名 modify 字段 字段的新類型
demo:
alter table ta0 modify uname int;