MySQL操作基本語法
阿新 • • 發佈:2018-12-13
建立表:
create table student(
id number(8) primary key not null,
name varchar(20) not null,
address varchar2(50) default '地址不詳'
);
插入資料:
insert into student(id,name) values(111,'名字');
刪除資料:
delete from student where id=111;
更新資料:
update student set name='名字' where name='姓名';
查詢資料:
select * from student;
新增新列:
alter table student add(sex varchars(4));
新增約束
alter table student add constraint ck_student_sex check(sex='男' OR sex='女');
新增外來鍵約束:
alter table stu1 add constraint fk_stu1_id foreign key(id) references stu2(id);
刪除約束
ALTER TABLE INFOS DROP CONSTRAINT CK_INFOS_UNIQUE;
修改資料型別:
alter table student modify(id number(4));
修改列名:
alter table student rename column sex to gender;
刪除列:
alter table student drop column gender;
修改表名:
alter table newstudent rename to student;
模糊查詢:
select * from student where sname like '張_%';
建立序列用於資料自增長:
create sequence myclass_id; 使用:myclass_id.nextval
增長步:
alter sequence myclass_id increment by 1;
刪除序列:
drop sequence myclass_id;
通過查詢從已有表建立另一個表:
create table 表名 as select <query>;
定義註冊使用者的儲存過程
DELIMITER $$
CREATE PROCEDURE register(IN userName VARCHAR(20),IN userPass VARCHAR(20),OUT userId INT)
BEGIN
INSERT INTO UserInfo(userName,userPass)VALUES(userName,userPass);
SELECT LAST_INSERT_ID() INTO userId;
END $$
使用觸發器實現使用者註冊業務
DELIMITER $$
CREATE TRIGGER tr_ register AFTER INSERT ON userinfo FOR EACH ROW
BEGIN
IN
SERT INTO userdetails(id) VALUES(NEW.id);
END $$;