完整性约束

 

范例1：定义member表，其中姓名不允许为空

DROP TABLE member PURGE ;

CREATE TABLE member(

    mid     NUMBER   ,

    name    VARCHAR2(200)   NOT NULL

) ;

范例2：向member表中增加正确的数据

INSERT INTO member(mid,name) VALUES (1,'李兴华') ;

 

范例3：向member表中增加错误的数据（两种语句的执行结果一样）

明确设置name字段为null：	INSERT INTO member(mid,name) VALUES (3,null) ;
不设置name字段的内容：	INSERT INTO member(mid) VALUES (3) ;

 

 

范例4：创建member表，在email字段上设置唯一约束

DROP TABLE member PURGE ;

CREATE TABLE member(

    mid     NUMBER   ,

    name    VARCHAR2(200)   NOT NULL ,

    email   VARCHAR2(50)    UNIQUE

) ;

范例5：向member表中增加正确记录

INSERT INTO member (mid,name,email) VALUES(1,'李兴华','mldnqa@163.com') ;

 

范例6：向member表中增加错误的纪录

INSERT INTO member (mid,name,email) VALUES(2,'董鸣楠','mldnqa@163.com') ;

范例：为唯一约束指定一个名字

DROP TABLE member PURGE ;

CREATE TABLE member(

    mid     NUMBER   ,

    name    VARCHAR2(200)    NOT NULL ,

    email   VARCHAR2(50)  ,

    CONSTRAINT uk_email      UNIQUE (email)

) ;

此时，再次执行两条插入语句，则错误提示将变为以下的内容。

 

范例：插入两条包含null的记录

INSERT INTO member (mid,name,email) VALUES(10,'魔乐科技',null) ;

INSERT INTO member (mid,name,email) VALUES(20,'MLDN',null) ;

 

范例：查询此时的member表内容

SELECT * FROM member ;

 

范例：设置member表中的mid为主键

DROP TABLE member PURGE ;

CREATE TABLE member(

    mid     NUMBER          PRIMARY KEY ,

    name    VARCHAR2(200)   NOT NULL ,

    email   VARCHAR2(50)  ,

    CONSTRAINT uk_email UNIQUE (email)

) ;

范例：将mid设置为null

INSERT INTO member (mid,name,email) VALUES(null,'李兴华','mldnqa@163.com') ;

范例：插入重复的mid

INSERT INTO member (mid,name,email) VALUES(1,'李兴华','mldnqa@163.com') ;

INSERT INTO member (mid,name,email) VALUES(1,'董鸣楠','mldnzhaopin@163.com') ;

范例：指定主键约束的名称

DROP TABLE member PURGE ;

CREATE TABLE member(

    mid     NUMBER       ,

    name    VARCHAR2(200)   NOT NULL ,

    email   VARCHAR2(50)  ,

    CONSTRAINT pk_mid PRIMARY KEY (mid) ,

    CONSTRAINT uk_email UNIQUE (email)

) ;

 

范例：将mid和name两个字段同时设置为主键

DROP TABLE member PURGE ;

CREATE TABLE member(

    mid     NUMBER  ,

    name    VARCHAR2(200)   NOT NULL ,

    email   VARCHAR2(50) ,

    CONSTRAINT pk_mid_name PRIMARY KEY (mid,name) ,

    CONSTRAINT uk_email UNIQUE (email)

) ;

范例：插入正确数据

INSERT INTO member (mid,name,email) VALUES(1,'李兴华','mldnqa@163.com') ;

INSERT INTO member (mid,name,email) VALUES(1,'董鸣楠','mldnzhaopin@163.com') ;

 

范例：插入错误的数据 —— mid和name相同

INSERT INTO member (mid,name,email) VALUES(1,'李兴华','mldnhr@163.com') ;

范例：查看member表数据

SELECT * FROM member ;

 

范例：在member表中增加age字段（年龄范围是0~200岁）和sex字段（只能是男或女）

DROP TABLE member PURGE ;

CREATE TABLE member(

    mid     NUMBER       ,

    name    VARCHAR2(200)   NOT NULL ,

    email   VARCHAR2(50)  ,

    age     NUMBER          CHECK (age BETWEEN 0 AND 200) ,

    sex     VARCHAR2(10) ,

    CONSTRAINT pk_mid_name PRIMARY KEY (mid,name) ,

    CONSTRAINT uk_email UNIQUE (email) ,

    CONSTRAINT ck_sex   CHECK (sex IN ('男','女'))

) ;

 

范例：插入正确的数据

INSERT INTO member (mid,name,email,age,sex) VALUES (1,'李兴华','mldnqa@163.com',30,'男') ;

范例：插入一条错误的数据，年龄为900岁

INSERT INTO member (mid,name,email,age,sex) VALUES (2,'董鸣楠','mldnzhaopin@163.com',900,'男') ;

范例：插入错误的数据，性别设置为“无”

INSERT INTO member (mid,name,email,age,sex) VALUES (2,'董鸣楠','mldnzhaopin@163.com',80,'无') ;

范例：根据给出的数据模型编写数据库创建脚本

DROP TABLE member PURGE ;

DROP TABLE advice PURGE ;

CREATE TABLE member (

    mid       NUMBER    ,

    name      VARCHAR2(200)   NOT NULL ,

    CONSTRAINT pk_mid PRIMARY KEY (mid)

) ;

CREATE TABLE advice (

    adid      NUMBER ,

    content   CLOB            NOT NULL ,

    mid      NUMBER ,

    CONSTRAINT pk_adid PRIMARY KEY (adid)

) ;

范例：插入正确的数据 —— 向member表插入两个会员信息

INSERT INTO member (mid,name) VALUES (1,'李兴华') ;

INSERT INTO member (mid,name) VALUES (2,'董鸣楠') ;

COMMIT ;

 

范例：查询member表数据

SELECT * FROM member ;

范例：插入正确的数据 —— 向advice表插入五条新记录

INSERT INTO advice (adid,content,mid) VALUES (1,'应该提倡内部沟通机制，设置总裁邮箱',1) ;

INSERT INTO advice (adid,content,mid) VALUES (2,'为了使公司内部良性发展，所有的部门领导应该重新应聘上岗',1) ;

INSERT INTO advice (adid,content,mid) VALUES (3,'要多开展员工培训活动，让员工更加有归属感',1) ;

INSERT INTO advice (adid,content,mid) VALUES (4,'应该开展多元化业务，更加满足市场需求',2) ;

INSERT INTO advice (adid,content,mid) VALUES (5,'大力发展技术部门，为本公司设计自己的ERP系统，适应电子化信息发展要求',2) ;

COMMIT ;

 

范例：查询advice表数据

SELECT * FROM advice ;

 

范例：查询出每位成员的完整信息以及所提出的意见数量

SELECT m.mid,m.name,COUNT(a.mid)

FROM member m,advice a

WHERE m.mid=a.mid

GROUP BY m.mid,m.name ;

 

范例：在意见表（advice）中增加以下错误的信息

INSERT INTO advice (adid,content,mid) VALUES (6,'岗位职责透明化',99) ;

 

范例：查询advice表数据

SELECT * FROM advice ;

 

范例：修改表结构，指定主-外键约束

DROP TABLE member PURGE ;

DROP TABLE advice PURGE ;

CREATE TABLE member (

    mid       NUMBER    ,

    name      VARCHAR2(200)   NOT NULL ,

    CONSTRAINT pk_mid PRIMARY KEY (mid)

) ;

CREATE TABLE advice (

    adid      NUMBER ,

    content   CLOB            NOT NULL ,

    mid       NUMBER ,

    CONSTRAINT pk_adid PRIMARY KEY (adid) ,

    CONSTRAINT fk_mid FOREIGN KEY(mid) REFERENCES member(mid)

) ;

 

范例：向advice表中插入错误的数据 —— 此时member表中没有mid=99的数据

INSERT INTO advice (adid,content,mid) VALUES (6,'岗位职责透明化',99) ;

 

范例：插入正确的数据

INSERT INTO member (mid,name) VALUES (1,'李兴华') ;

INSERT INTO member (mid,name) VALUES (2,'董鸣楠') ;

INSERT INTO advice (adid,content,mid) VALUES (1,'应该提倡内部沟通机制，设置总裁邮箱',1) ;

INSERT INTO advice (adid,content,mid) VALUES (3,'要多开展员工培训活动，让员工更加有归属感',2) ;

COMMIT ;

范例：删除member表中编号为“1”的数据（mid=1），此时没有删除子表（advice）数据

DELETE FROM member WHERE mid=1 ;

范例：先删除子表（advice）中mid=1的数据，之后再删除父表（member）中mid=1的数据

DELETE FROM advice WHERE mid=1 ;

DELETE FROM member WHERE mid=1 ;

COMMIT ;

 

范例：查询member表中的记录

SELECT * FROM member ;

 

范例：修改表创建语法，增加级联删除，同时配置测试数据

DROP TABLE advice PURGE ;

DROP TABLE member PURGE ;

CREATE TABLE member (

    mid       NUMBER    ,

    name      VARCHAR2(200)   NOT NULL ,

    CONSTRAINT pk_mid PRIMARY KEY (mid)

) ;

CREATE TABLE advice (

    adid      NUMBER ,

    content   CLOB            NOT NULL ,

    mid       NUMBER ,

    CONSTRAINT pk_adid PRIMARY KEY (adid) ,

    CONSTRAINT fk_mid FOREIGN KEY(mid) REFERENCES member(mid) ON DELETE CASCADE

) ;

INSERT INTO member (mid,name) VALUES (1,'李兴华') ;

INSERT INTO member (mid,name) VALUES (2,'董鸣楠') ;

INSERT INTO advice (adid,content,mid) VALUES (1,'应该提倡内部沟通机制，设置总裁邮箱',1) ;

INSERT INTO advice (adid,content,mid) VALUES (3,'要多开展员工培训活动，让员工更加有归属感',2) ;

COMMIT ;

范例：查询member表中的当前数据

SELECT * FROM member ;

 

范例：查询advice表中的当前数据

SELECT * FROM advice ;

 

范例：删除member表中编号为1的成员信息

DELETE FROM member WHERE mid=1 ;

 

范例：查询member表记录

SELECT * FROM member ;

 

范例：查询advice表记录

SELECT * FROM advice ;

 

范例：修改表的创建语句，增加ON DELETE SET NULL子句

DROP TABLE advice PURGE ;

DROP TABLE member PURGE ;

CREATE TABLE member (

    mid       NUMBER    ,

    name      VARCHAR2(200)   NOT NULL ,

    CONSTRAINT pk_mid PRIMARY KEY (mid)

) ;

CREATE TABLE advice (

    adid      NUMBER ,

    content   CLOB            NOT NULL ,

    mid       NUMBER ,

    CONSTRAINT pk_adid PRIMARY KEY (adid) ,

    CONSTRAINT fk_mid FOREIGN KEY(mid) REFERENCES member(mid) ON DELETE SET NULL

) ;

INSERT INTO member (mid,name) VALUES (1,'李兴华') ;

INSERT INTO member (mid,name) VALUES (2,'董鸣楠') ;

INSERT INTO advice (adid,content,mid) VALUES (1,'应该提倡内部沟通机制，设置总裁邮箱',1) ;

INSERT INTO advice (adid,content,mid) VALUES (3,'要多开展员工培训活动，让员工更加有归属感',2) ;

COMMIT ;

范例：删除member表中mid为1的记录

DELETE FROM member WHERE mid=1 ;

 

范例：查询member表记录

SELECT * FROM member ;

 

范例：查询advice表中的记录

SELECT * FROM advice ;

 

范例：直接删除父表（member）

DROP TABLE member ;

范例：先删除子表（advice），再删除父表（member）。

DROP TABLE advice PURGE ;

DROP TABLE member PURGE ;

范例：强制性删除member表

DROP TABLE member CASCADE CONSTRAINT ;

范例：查看全部的约束名称、类型、约束设置对应的表名称

SELECT constraint_name,constraint_type,table_name FROM user_constraints ;

 

范例：查询emp表上的全部约束

SELECT constraint_name,constraint_type,table_name

FROM user_constraints WHERE table_name='EMP' ;

 

范例：查询user_cons_columns数据字典

SELECT * FROM user_cons_columns ;

 

范例：假设有如下的一张表

DROP TABLE member purge ;

CREATE TABLE member(

mid NUMBER ,

name VARCHAR2(30)  ,

age NUMBER

) ;

 

范例：查看member表中的约束

SELECT constraint_name,constraint_type,table_name

FROM user_constraints WHERE table_name='MEMBER' ;

 

范例：为member表的mid字段增加主键约束

ALTER TABLE member ADD CONSTRAINT pk_mid PRIMARY KEY(mid) ;

 

范例：为member表的age增加检查约束

ALTER TABLE member ADD CONSTRAINT ck_age CHECK(age BETWEEN 0 AND 200) ;

为表中添加完约束之后，下面可以通过数据字典user_constraints查看member表中的全部约束。

 

范例：查看member表中的约束

SELECT constraint_name,constraint_type,table_name

FROM user_constraints WHERE table_name='MEMBER' ;

 

范例：为name字段设置非空约束

ALTER TABLE member MODIFY (name VARCHAR2(30) NOT NULL) ;

 

范例：给出要操作的数据表

DROP TABLE advice PURGE ;

DROP TABLE member PURGE ;

CREATE TABLE member (

    mid       NUMBER    ,

    name      VARCHAR2(200)   NOT NULL ,

    CONSTRAINT pk_mid PRIMARY KEY (mid)

) ;

CREATE TABLE advice (

    adid      NUMBER ,

    content   CLOB            NOT NULL ,

    mid       NUMBER ,

    CONSTRAINT pk_adid PRIMARY KEY (adid) ,

    CONSTRAINT fk_mid FOREIGN KEY(mid) REFERENCES member(mid) ON DELETE SET NULL

) ;

INSERT INTO member (mid,name) VALUES (1,'李兴华') ;

INSERT INTO member (mid,name) VALUES (2,'董鸣楠') ;

INSERT INTO advice (adid,content,mid) VALUES (1,'应该提倡内部沟通机制，设置总裁邮箱',1) ;

INSERT INTO advice (adid,content,mid) VALUES (2,'为了使公司内部良性发展，所有的部门领导应该重新应聘上岗',1) ;

INSERT INTO advice (adid,content,mid) VALUES (3,'要多开展员工培训活动，让员工更加有归属感',1) ;

INSERT INTO advice (adid,content,mid) VALUES (4,'应该开展多元化业务，更加满足市场需求',2) ;

INSERT INTO advice (adid,content,mid) VALUES (5,'大力发展技术部门，为本公司设计自己的ERP系统，适应电子化信息发展要求',2) ;

COMMIT ;

 

范例：禁用advice表中的adid主键约束“pk_adid”

ALTER TABLE advice DISABLE CONSTRAINT pk_adid ;

 

范例：查询禁用约束之后advice表中的数据

SELECT * FROM advice ;

 

范例：禁用member表中的“pk_mid”约束，此字段在advice表中是外键

ALTER TABLE member DISABLE CONSTRAINT pk_mid ;

范例：增加两条MID相同的数据

INSERT INTO member(mid,name) VALUES (1,'MLDN') ;

INSERT INTO member(mid,name) VALUES (1,'魔乐科技') ;

 

范例：查询member表中的记录

SELECT * FROM member ;

 

范例：重新启动member表中的主键约束“pk_mid”

ALTER TABLE member ENABLE CONSTRAINT pk_mid ;

 

范例：重新启动advice表中的主键约束“pk_adid”

ALTER TABLE advice ENABLE CONSTRAINT pk_adid ;

 

范例：删除advice表之中的“pk_adid”约束 —— 无关联外键

ALTER TABLE advice DROP CONSTRAINT pk_adid ;

 

范例：删除member表之中的“pk_mid”约束 —— 有关联外键

ALTER TABLE member DROP CONSTRAINT pk_mid CASCADE ;

 

范例：定义数据库创建脚本

-- 删除数据表

DROP TABLE grade ;

DROP TABLE sporter ;

DROP TABLE item ;

PURGE RECYCLEBIN ;

-- 创建数据表

CREATE TABLE sporter(

sporterid NUMBER(4) ,

name VARCHAR2(30) NOT NULL ,

sex VARCHAR2(10) ,

department VARCHAR2(30) NOT NULL ,

CONSTRAINT pk_sporterid PRIMARY KEY (sporterid) ,

CONSTRAINT ck_sex CHECK (sex IN ('男','女'))

) ;

CREATE TABLE item(

itemid VARCHAR2(4) ,

itemname VARCHAR2(30) NOT NULL ,

location VARCHAR2(30) NOT NULL ,

CONSTRAINT pk_itemid PRIMARY KEY (itemid)

) ;

CREATE TABLE grade(

sporterid NUMBER(4) ,

itemid VARCHAR2(4)  ,

mark NUMBER(1) ,

CONSTRAINT fk_sporterid FOREIGN KEY (sporterid) REFERENCES sporter(sporterid) ON DELETE CASCADE ,

CONSTRAINT fk_itemid FOREIGN KEY (itemid) REFERENCES item(itemid) ON DELETE CASCADE ,

CONSTRAINT ck_mark CHECK (mark IN (6,4,2,0))

) ;

范例：查询全部数据表

SELECT * FROM tab WHERE tname IN ('SPORTER','ITEM','GRADE') ;

 

范例：查询三张数据表中的约束

SELECT constraint_name,constraint_type,table_name

FROM user_constraints

WHERE table_name IN ('SPORTER','ITEM','GRADE')

ORDER BY table_name;

INSERT INTO sporter(sporterid,name,sex,department) VALUES (1001,'李明','男','计算机系') ;

INSERT INTO sporter(sporterid,name,sex,department) VALUES (1002,'张三','男','数学系') ;

INSERT INTO sporter(sporterid,name,sex,department) VALUES (1003,'李四','男','计算机系') ;

INSERT INTO sporter(sporterid,name,sex,department) VALUES (1004,'王二','男','物理系') ;

INSERT INTO sporter(sporterid,name,sex,department) VALUES (1005,'李娜','女','心理系') ;

INSERT INTO sporter(sporterid,name,sex,department) VALUES (1006,'孙丽','女','数学系') ;

COMMIT ;

 

范例：验证sporter表数据是否已经成功插入

SELECT * FROM sporter ;

INSERT INTO item(itemid,itemname,location) VALUES ('x001','男子五千米','一操场') ;

INSERT INTO item(itemid,itemname,location) VALUES ('x002','男子标枪','一操场') ;

INSERT INTO item(itemid,itemname,location) VALUES ('x003','男子跳远','二操场') ;

INSERT INTO item(itemid,itemname,location) VALUES ('x004','女子跳高','二操场') ;

INSERT INTO item(itemid,itemname,location) VALUES ('x005','女子三千米','三操场') ;

COMMIT ;

 

范例：验证item表数据是否已经成功插入

SELECT * FROM item ;

 

INSERT INTO grade(sporterid,itemid,mark) VALUES (1001,  'x001', 6) ;

INSERT INTO grade(sporterid,itemid,mark) VALUES (1002,  'x001', 4) ;

INSERT INTO grade(sporterid,itemid,mark) VALUES (1003,  'x001', 2) ;

INSERT INTO grade(sporterid,itemid,mark) VALUES (1004,  'x001', 0) ;

INSERT INTO grade(sporterid,itemid,mark) VALUES (1001,  'x003', 4) ;

INSERT INTO grade(sporterid,itemid,mark) VALUES (1002,  'x003', 6) ;

INSERT INTO grade(sporterid,itemid,mark) VALUES (1004,  'x003', 2) ;

INSERT INTO grade(sporterid,itemid,mark) VALUES (1003,  'x003', 0) ;

INSERT INTO grade(sporterid,itemid,mark) VALUES (1005,  'x004', 6) ;

INSERT INTO grade(sporterid,itemid,mark) VALUES (1006,  'x004', 4) ;

INSERT INTO grade(sporterid,itemid,mark) VALUES (1001,  'x004', 2) ;

INSERT INTO grade(sporterid,itemid,mark) VALUES (1002,  'x004', 0) ;

INSERT INTO grade(sporterid,itemid,mark) VALUES (1003,  'x002', 6) ;

INSERT INTO grade(sporterid,itemid,mark) VALUES (1005,  'x002', 4) ;

INSERT INTO grade(sporterid,itemid,mark) VALUES (1006,  'x002', 2) ;

INSERT INTO grade(sporterid,itemid,mark) VALUES (1001,  'x002', 0) ;

COMMIT ;

 

范例：验证grade表数据是否已经成功插入

SELECT * FROM grade ;

 

【第一题】、求出目前总积分最高的系名及其积分。

SELECT s.department,g.mark

FROM sporter s,grade g

WHERE s.sporterid=g.sporterid ;

SELECT s.department,SUM(g.mark)

FROM sporter s,grade g

WHERE s.sporterid=g.sporterid

GROUP BY s.department ;

SELECT MAX(SUM(g.mark))

FROM sporter s,grade g

WHERE s.sporterid=g.sporterid

GROUP BY s.department ;

SELECT s.department,SUM(g.mark)

FROM sporter s,grade g

WHERE s.sporterid=g.sporterid

GROUP BY s.department

HAVING SUM(g.mark)=(

SELECT MAX(SUM(g.mark))

FROM sporter s,grade g

WHERE s.sporterid=g.sporterid

GROUP BY s.department) ;

 

【第二题】、找出在一操场进行比赛的各项目名称及其冠军的姓名

SELECT i.itemid,g.mark

FROM item i,grade g

WHERE i.itemid=g.itemid

AND

i.location='一操场' ;

SELECT i.itemid,MAX(g.mark)

FROM item i,grade g

WHERE i.itemid=g.itemid

AND

i.location='一操场'

GROUP BY i.itemid ;

SELECT i.itemname,s.name,g.mark

FROM sporter s,item i,grade g

WHERE s.sporterid=g.sporterid

AND

i.itemid=g.itemid

AND

i.location='一操场' ;

SELECT i.itemname,s.name

FROM sporter s,item i,grade g,(

SELECT i.itemid iid,MAX(g.mark) max

FROM item i,grade g

WHERE i.itemid=g.itemid

AND

i.location='一操场'

GROUP BY i.itemid ) temp

WHERE s.sporterid=g.sporterid

AND

i.itemid=g.itemid

AND

i.location='一操场'

AND

i.itemid=temp.iid

AND

g.mark=temp.max ;

 

【第三题】、找出参加了张三所参加过的项目的其他同学的姓名

SELECT sporterid

FROM sporter

WHERE name='张三' ;

SELECT itemid

FROM grade

WHERE sporterid=(

SELECT sporterid

        FROM sporter

        WHERE name='张三') ;

SELECT DISTINCT sporterid

FROM grade

WHERE itemid IN (

SELECT itemid

        FROM grade

        WHERE sporterid=(

SELECT sporterid

                FROM sporter

                WHERE name='张三')) ;

SELECT name

FROM sporter

WHERE sporterid IN(

SELECT sporterid

        FROM grade

        WHERE itemid IN (

SELECT itemid

                FROM grade

                WHERE sporterid=(

SELECT sporterid

                        FROM sporter

                        WHERE name='张三')))

AND name<>'张三' ;

 

【第四题】、经查张三因为使用了违禁药品，其成绩都记0分，请在数据库中作出相应修改。

UPDATE grade SET mark=0

WHERE sporterid=(

    SELECT sporterid

    FROM sporter

    WHERE name='张三') ;

SELECT s.name,g.itemid,g.mark

FROM sporter s , grade g

WHERE s.sporterid=g.sporterid AND s.name='张三' ;

 

【第五题】、经组委会协商，需要删除女子跳高比赛项目。

DELETE FROM item WHERE itemname='女子跳高' ;

 

范例：查询项目表中是否已经成功删除

SELECT * FROM item WHERE itemname='女子跳高' ;