CREATE TABLE department(
deptNo NUMBER(2) NOT NULL,
deptName VARCHAR2(20) NOT NULL,
LOCATION VARCHAR(20) DEFAULT '青岛'
);
--创建表同时，填充数据
CREATE TABLE emp_new(NAME,job,salary,hiredate)
AS
SELECT ename,job,sal,hiredate FROM emp WHERE deptno=30;
SELECT * FROM emp_new;
--给表重命名
RENAME emp_new TO emp_new_test;
--对表进行修改 ALTER TABLE department
--为表添加字段
ALTER TABLE department ADD(info VARCHAR2(400));
--修改表中的字段
ALTER TABLE department MODIFY(info VARCHAR2(800));
--删除表中的字段
ALTER TABLE department DROP(info);
--给表添加注释
COMMENT ON TABLE department IS '部门信息表';
--给表中的列添加注释
COMMENT ON COLUMN department.location IS '部门所在地';
SELECT * FROM emp_new_test;
DELETE FROM emp_new_test ;
TRUNCATE TABLE emp_new_test;
DROP TABLE emp_new_test CASCADE CONSTRAINTS;
--单索引
CREATE INDEX idx_deptno ON department(deptno);
--复合索引
CREATE INDEX idx_deptno_deptname ON department(deptno,deptname);
--唯一索引
CREATE UNIQUE INDEX idx_uq_deptname ON department(deptname);
--重建索引
ALTER INDEX idx_uq_deptname REBUILD;
--删除索引
DROP INDEX idx_uq_deptname;
--约束的类型：
--1.not null
--约束可以在创建表的时候
CREATE TABLE employee(
eno NUMBER(5) NOT NULL,
ename VARCHAR2(10) NOT NULL,
age NUMBER(2) NOT NULL,
phone VARCHAR2(16)
);
--修改表的时候
ALTER TABLE employee MODIFY phone NOT NULL;
--2.unique
DROP TABLE employee;
CREATE TABLE employee(
eno NUMBER(5) NOT NULL,
ename VARCHAR2(10) NOT NULL UNIQUE,--1
age NUMBER(2) NOT NULL,
phone VARCHAR2(16)
);
DROP TABLE employee;
CREATE TABLE employee(
eno NUMBER(5) NOT NULL,
ename VARCHAR2(10) NOT NULL,
age NUMBER(2) NOT NULL,
phone VARCHAR2(16),
CONSTRAINT uq_phone UNIQUE(phone) --2
);
ALTER TABLE employee ADD CONSTRAINT uq_phone UNIQUE(phone);--3
--3 primary key
DROP TABLE employee;
CREATE TABLE employee(
eno NUMBER(5) NOT NULL PRIMARY KEY,--1
ename VARCHAR2(10) NOT NULL,
age NUMBER(2) NOT NULL,
phone VARCHAR2(16)
);
DROP TABLE employee;
CREATE TABLE employee(
eno NUMBER(5) NOT NULL,
ename VARCHAR2(10) NOT NULL,
age NUMBER(2) NOT NULL,
phone VARCHAR2(16),
CONSTRAINT pk_eno PRIMARY KEY (eno)--2
);
DROP TABLE employee;
CREATE TABLE employee(
eno NUMBER(5) NOT NULL ,
ename VARCHAR2(10) NOT NULL,
age NUMBER(2) NOT NULL,
phone VARCHAR2(16)
);
ALTER TABLE employee ADD CONSTRAINT pk_eno PRIMARY KEY (eno); --3
--4 foreign key
DROP TABLE department;
CREATE TABLE department(
deptNo NUMBER(2) NOT NULL PRIMARY KEY,
deptName VARCHAR2(20) NOT NULL,
LOCATION VARCHAR(20) DEFAULT '青岛'
);
DROP TABLE employee;
CREATE TABLE employee(
eno NUMBER(5) NOT NULL ,
ename VARCHAR2(10) NOT NULL,
age NUMBER(2) NOT NULL,
phone VARCHAR2(16),
deptNo NUMBER(2) CONSTRAINT fk_department_deptno REFERENCES department(deptno) --1
);
DROP TABLE employee;
CREATE TABLE employee(
eno NUMBER(5) NOT NULL ,
ename VARCHAR2(10) NOT NULL,
age NUMBER(2) NOT NULL,
phone VARCHAR2(16),
deptNo NUMBER(2) ,
CONSTRAINT fk_department_deptno FOREIGN KEY(deptNo) REFERENCES department(deptno) --2
);
DROP TABLE employee;
CREATE TABLE employee(
eno NUMBER(5) NOT NULL ,
ename VARCHAR2(10) NOT NULL,
age NUMBER(2) NOT NULL,
phone VARCHAR2(16),
deptNo NUMBER(2)
);
ALTER TABLE employee ADD CONSTRAINT fk_department_deptno FOREIGN KEY(deptNo) REFERENCES department(deptno) --3
--check约束
DROP TABLE employee;
CREATE TABLE employee(
eno NUMBER(5) NOT NULL ,
ename VARCHAR2(10) NOT NULL,
age NUMBER(2) NOT NULL CHECK(age BETWEEN 18 AND 70),--1
phone VARCHAR2(16),
deptNo NUMBER(2)
);
DROP TABLE employee;
CREATE TABLE employee(
eno NUMBER(5) NOT NULL ,
ename VARCHAR2(10) NOT NULL CHECK(LENGTH(ename)<=5),
age NUMBER(2) NOT NULL,
phone VARCHAR2(16),
deptNo NUMBER(2),
CONSTRAINT ck_age CHECK(age BETWEEN 18 AND 70) --2
);
DROP TABLE employee;
CREATE TABLE employee(
eno NUMBER(5) NOT NULL ,
ename VARCHAR2(10) NOT NULL,
age NUMBER(2) NOT NULL ,
phone VARCHAR2(16),
deptNo NUMBER(2)
);
ALTER TABLE employee ADD CONSTRAINT ck_age CHECK(age BETWEEN 18 AND 70); --3
ALTER TABLE employee RENAME CONSTRAINT ck_age TO ck_age_now;
ALTER TABLE employee DISABLE CONSTRAINT ck_age_now;
ALTER TABLE employee ENABLE CONSTRAINT ck_age_now;
ALTER TABLE employee DROP CONSTRAINT ck_age_now;
ALTER TABLE employee ADD CONSTRAINT pk_eno PRIMARY KEY (eno);
ALTER TABLE employee DROP CONSTRAINT pk_eno;
--数据操作
DROP TABLE department;
CREATE TABLE department(
deptNo NUMBER(2) NOT NULL PRIMARY KEY,
deptName VARCHAR2(20) NOT NULL,
LOCATION VARCHAR(20) DEFAULT '青岛'
);
DROP TABLE employee;
CREATE TABLE employee(
eno NUMBER(5) NOT NULL ,
ename VARCHAR2(10) NOT NULL,
age NUMBER(2) DEFAULT 20 CHECK(age BETWEEN 18 AND 70) ,
salary NUMBER(7,2),
phone VARCHAR2(16),
hiredate DATE NOT NULL ,
deptNo NUMBER(2) CONSTRAINT fk_department_deptno REFERENCES department(deptno)
);
INSERT INTO department VALUES(10,'市场一部','青岛');
INSERT INTO department(deptno,deptName) VALUES(20,'市场二部');
INSERT INTO department(deptName,deptno) VALUES('市场三部',30);
INSERT INTO employee VALUES(10001,'张三',25,2300,'',SYSDATE,10);
INSERT INTO employee VALUES(10002,'李四',30,3800,'',to_date('2013-6-25','yyyy-MM-dd'),20);
INSERT INTO department VALUES(&deptno,'&deptName','&LOCATION');
INSERT INTO employee (eno,ename,salary,hiredate,deptno)
SELECT empno,ename,sal,hiredate,deptno FROM emp WHERE deptno=30;
UPDATE employee SET salary=salary*1.1 WHERE hiredate<to_date('2012-1-1','yyyy-MM-dd');
UPDATE employee SET age=trunc(dbms_random.value(18,70)) WHERE deptno=30 ;
UPDATE employee SET age=DEFAULT WHERE ename='ALLEN';
DELETE FROM employee WHERE eno=7900;
COMMIT;
ROLLBACK;
SELECT * FROM employee;
SELECT * FROM department;
SELECT * FROM emp;
SELECT dbms_random.value,dbms_random.value(0,100) FROM dual;
---序列
create sequence SEQ_EMPLOYEE
minvalue 1
maxvalue 999999999
start with 2
increment by 2
cache 20;
SELECT SEQ_EMPLOYEE.Nextval FROM dual;
SELECT SEQ_EMPLOYEE.CURRVAL FROM dual;
INSERT INTO employee VALUES(SEQ_EMPLOYEE.Nextval,'张三',25,2300,'',SYSDATE,10);
COMMIT;
SELECT * FROM employee;
DROP SEQUENCE SEQ_EMPLOYEE;
--视图
--简单视图
CREATE VIEW vw_emp AS
SELECT empno,ename,hiredate FROM emp;
CREATE VIEW vw_emp1 AS
SELECT ename,hiredate,sal,comm FROM emp;
SELECT * FROM vw_emp;
SELECT * FROM vw_emp1;
--复杂视图
CREATE VIEW vm_emp3(deptno,ecount,avgsal) AS
SELECT deptno,COUNT(1),round(AVG(sal),2) FROM emp GROUP BY deptno;
RENAME vm_emp3 TO vw_emp3;
SELECT * FROM vw_emp3;
--连接视图
CREATE VIEW vw_emp4 AS
SELECT e.empno,e.ename,d.dname,d.loc
FROM emp e,dept d
WHERE e.deptno=d.deptno;
SELECT ename,dname FROM vw_emp4;
--只读视图
CREATE VIEW vw_emp5 AS
SELECT * FROM emp WITH READ ONLY;
SELECT * FROM vw_emp5;