首先建表：

--学生表(学号，姓名，性别，出生日期，年级，电话,家住地址)
create table student(
stuno number(5,0) primary key, --学号
stuname varchar2(30) not null, --姓名
sex char(2) default(‘男‘) check(sex=‘男‘ or sex=‘女‘) not null ,
birthday date not null,
gradeid number(5,0) not null,
moible varchar2(15) not null,
address varchar2(50) null
)
--年级表(年级编号,年级名称)
create table grade(
gradeid number(5,0) primary key, --年级编号
gradename varchar2(30) not null --年级名称
)

--课程表(课程编号，课程名，所属的年级，学时)
create table course(
courseid number(5,0) primary key, --课程编号
coursename varchar2(30) not null,--课程名称
gradeid number(5,0) not null ,--所属年级编号
hours number(3,0) default(0) --学时
)
--成绩表(学号，课程编号，成绩)
create table chenji(
stuno number(5,0) not null , --学号
courseid number(5,0) not null ,--课程号
score number(4,1) check(score<=100 and score>=0)
)

select * from grade;
select * from chenji;
select * from course;
select * from student;

--学生表关联到年级表 学生表从表，年级表是主表
--增加外键关联
alter table student add constraint FK_stu_grade foreign key (gradeid)
references grade(gradeid)
--课程表关联到年级表 课程表是从表，年级表是主表
alter table course add constraint FK_course_grade foreign key (gradeid)
references grade(gradeid)
--主键约束,给成绩表增加主键约束
alter table chenji add constraint PK_chenji primary key(stuno,courseid)
--成绩表中的学号关联到学生表的学号,学生表是主表，成绩表是从表

alter table chenji add constraint FK_chenj_student foreign key (stuno)
references student(stuno)
--成绩表中的课程号关联到课程表中的课程号
alter table chenji add constraint FK_chenji_course foreign key (courseid)
references course(courseid)

--添加默认值约束
alter table student MODIFY (address default ‘深圳‘)
--添加check约束
alter table student add constraint CK_student_sex check(sex=‘男‘ or sex=‘女‘)
--删除约束
alter table student drop constraint CK_student_sex

create table gradeTable(
gradeid number(3,0) primary key,
gradename varchar2(20) not null
)
--建表时建外键
create table test1(
id number(3,0) primary key,
name varchar2(20) not null,
gradeid number(3,0) not null,
foreign key (gradeid) references gradeTable(gradeid)
)

--创建序列
create sequence grade_seq --产生一个从1开始每次增长1的一个序列
--删除序列
drop sequence grade_seq
--创建序列-指定启始值，增长值,最大值
create sequence grade_seq
start with 100
increment by 1
nomaxvalue
--修改序列
alter sequence grade_seq
increment by 1
nomaxvalue
--创建递减序列
create sequence grade_seq2
start with 100
maxvalue 100
increment by -1
minvalue -999999999999

select * from grade
--向年级表中插入数据
insert into grade(gradeid,gradename) values (grade_seq.nextval,‘一年级‘);
insert into grade(gradeid,gradename) values (grade_seq.nextval,‘二年级‘);
insert into grade(gradeid,gradename) values (grade_seq.nextval,‘三年级‘);
insert into grade(gradeid,gradename) values (grade_seq.nextval,‘四年级‘);
insert into grade(gradeid,gradename) values (grade_seq.nextval,‘五年级‘);
insert into grade(gradeid,gradename) values (grade_seq.nextval,‘六年级‘);
insert into grade(gradeid,gradename) values (grade_seq.nextval,‘初一年级‘);
insert into grade values (grade_seq.nextval,‘初二年级‘);

--学生表插入数据
select * from student
--创建学生表的序列
create sequence stu_seq
start with 1000
increment by 1
nomaxvalue
cache 10;

select * from student
--SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");

insert into student values (stu_seq.nextval,‘张三‘,default,‘10-9月-1990‘,1,‘13211111111‘,‘深圳福田‘);
insert into student values (stu_seq.nextval,‘李四‘,default,to_date(‘1990-10-22‘,‘YYYY-MM-DD‘),1,‘13211111111‘,‘深圳福田‘);
insert into student values (stu_seq.nextval,‘王五‘,default,to_date(‘1991-2-12 10:30:10‘,‘YYYY-MM-DD HH:mi:ss‘),1,‘13211111111‘,‘深圳福田‘);
insert into student values (stu_seq.nextval,‘赵五‘,‘女‘,to_date(‘1991-2-12 10:30:10‘,‘YYYY-MM-DD HH:mi:ss‘),1,‘13211111111‘,‘深圳福田‘);

insert into student values (stu_seq.nextval,‘张四‘,default,‘10-9月-1990‘,3,‘13211111111‘,‘深圳宝安‘);
insert into student values (stu_seq.nextval,‘李四‘,‘女‘,to_date(‘1993-10-22‘,‘YYYY-MM-DD‘),4,‘13211111111‘,‘深圳罗湖‘);
insert into student values (stu_seq.nextval,‘赵五‘,default,to_date(‘1996-2-12 10:30:10‘,‘YYYY-MM-DD HH:mi:ss‘),3,‘13211111111‘,‘深圳南山‘);
insert into student values (stu_seq.nextval,‘赵六‘,‘女‘,to_date(‘1991-2-12 10:30:10‘,‘YYYY-MM-DD HH:mi:ss‘),5,‘13211111111‘,‘深圳福田‘);
insert into student values (stu_seq.nextval,‘张三三‘,default,to_date(‘1996-2-12 10:30:10‘,‘YYYY-MM-DD HH:mi:ss‘),3,‘13211111111‘,‘深圳南山‘);
insert into student values (stu_seq.nextval,‘张四四‘,‘女‘,to_date(‘1991-2-12 10:30:10‘,‘YYYY-MM-DD HH:mi:ss‘),5,‘13211111111‘,‘深圳福田‘);
insert into student values (stu_seq.nextval,‘张王‘,default,to_date(‘1996-2-12 10:30:10‘,‘YYYY-MM-DD HH:mi:ss‘),3,‘13211111111‘,null);
insert into student values (stu_seq.nextval,‘张六‘,‘女‘,to_date(‘1991-2-12 10:30:10‘,‘YYYY-MM-DD HH:mi:ss‘),5,‘13211111111‘,‘‘);

--向课程表中插入数据
insert into course values(100,‘java‘,101,60);
insert into course values(101,‘oracle‘,102,50);
insert into course values(102,‘html‘,101,40);
insert into course values(103,‘jQuery‘,102,48);

insert into course values(104,‘css‘,101,30);
insert into course values(105,‘JS‘,104,48);
insert into course values(106,‘SSH‘,106,80);
insert into course values(107,‘uml‘,103,48);

--修改学号为1001性别为‘女‘
update student set sex=‘女‘ where stuno=1001
update student set sex=‘男‘,address=‘广州花都‘ where stuno=1001
--删除性别为女的学生
delete from student where sex=‘女‘
--删除学生表中所有记录
delete from student
--truncate删除学生表中所有记录
--delete 和truncate,drop异同
--相同点：都可以删除表中记录
--不同点：1，truncate不能接条件，将表中记录全部删除；而delete可以接where条件，可以条件删除
--2.truncate删除表中记录时，如果表中主外键关联，不论是否有关联的数据，均无法执行
delete 没有关联到 数可以删除，如果数据有关联到其他表，则悬赏从表记录在删除主标记录
--3.truncate删除表时，不会记录到日志，不能回滚，删除数据不可恢复，也不会触发表中删除数据的触发器，执行速度快
--delete 删除数据会记录到日志，可以回滚，可恢复，会触发表中删除记录的触发器，执行速度慢
--delete 和 truncate 只删除表中数据，表还在
--drop 指的是删除表，表中的约束都会删除
--可以用sys_guid() 或序列产生主键
select sys_guid() from dual;

truncate table student;
select * from student;

insert into chenji values (1013,100,90);
insert into chenji values (1013,102,80);
insert into chenji values (1013,104,73);
insert into chenji values (1015,100,91);
insert into chenji values (1015,102,90);
insert into chenji values (1020,104,98);

insert into gradetable values (1,‘aa‘);
insert into gradetable values (2,‘ada‘);
insert into gradetable values (3,‘aad‘);
insert into gradetable values (4,‘aaa‘);
commit;
truncate table gradetable;

drop table gradetable;

select grade_seq2.nextval from dual;
delete from grade where gradeid>10;

select * from student;
select * from grade;
select * from course;
select * from chenji;

--查询所有男生信息
select * from student where sex=‘男‘;
--查询家住地址是深圳南山的学生的学号，姓名，性别，生日
select stuno,stuname,sex,birthday from student where address=‘深圳南山‘;
--查询年级编号为1的深圳的女同学
select * from student where gradeid=1 and address like ‘深圳%‘ and sex=‘女‘

--模糊查询
--like和not like --通配符%表示0个或多个任意字符 _表示一个任意字符
--查询学生表中姓张的同学的学号，姓名，性别。年龄
select stuno,stuname,sex,birthday from student where stuname like ‘张%‘
--查询学生表中姓张的同学的学号，姓名，性别，年龄，名字是三个字
select stuno,stuname,sex,birthday from student where stuname like ‘张__‘

--in和not in
select * from student where stuno=1008 or stuno=1018 or stuno=1022
--等价于
select * from student where stuno in (1008,1018,1022)
select * from course;

--查询jvaa, oracle，jquery三门课的课程情况
select * from course where coursename in(‘java‘,‘oracle‘,‘jQuery‘)

--查询不是java ,oracle,jQuery三门课的课程情况
select * from course where coursename not in(‘java‘,‘oracle‘,‘jQuery‘)

--between ...and...
--查询学时在30到60之间课程的信息[30,60] 相当于>=30 and <=60
select * from course where hours between 30 and 60
--等价于
select * from course where hours<=60 and hours>=30

--查询学生成绩不等90分的成绩信息
select * from chenji where score<>90.0
--null 和 not null
--查询地址为空的学生的信息
select * from student where address is null;
--查询地址部位空的学生的信息
select * from student where address is not null;

--聚合函数 max(),min(),avg(),count(),sum()
--查询学时最多的那门课的信息
select * from course where hours=(select max(hours) from course)
--查询学时最少的那门课的信息
select * from course where hours=(select min(hours) from course)
select * from chenji;
--课程编号为100这门课的平均分
select avg(score) from chenji where courseid=100
--所有课程的平均学时
select avg(hours) from course
--求学号为1013这个学生的总分
select stuno,sum(score) from chenji where stuno=1013
group by stuno
--注意：查询的列中除了聚合函数那一列的其它列都必须作为group by 的条件
--统计课程号为100这门课，成绩大于80分的个数
select count(*) from chenji where score>80 and courseid=100
--统计学生表中年级一年级的人数
--方法一
select count(*) from student
where gradeid in (select gradeid from grade where gradename=‘一年级‘);

--方法二
select count(*) from student s,grade g
where s.gradeid=g.gradeid
and g.gradename=‘一年级‘

--查询一年级学生的学号，姓名，性别，年级名称
select stuno as 学号,stuname 姓名,sex 性别,gradename 年级
from student s,grade g
where s.gradeid=g.gradeid
and g.gradename=‘一年级‘

--查询一年级的年级编号
select gradeid from grade where gradename=‘一年级‘

Oracle基础操作