oracle DDL（数据定义语言）基本语句

--创建表格

create table  production(

ProductIdvarchar2(10),

ProductNamevarchar2(20),

ProductPricenumber(8,2),

Quantitynumber(10),

Categoryvarchar2(10),

Desperationvarchar2(1000),

Originvarchar2(10)

)

--添加一列

alter table production

add remark varchar2(200);

select * from production

--修改列类型

alter table production

modify remark number(2,2)

--删除一列

alter table production

drop column remark

create table categoryinfo(

CategotyIdvarchar2(10),

CategoryNamevarchar2(30)

);

alter table categoryInfo

DROP COLUMN CategotyId;

alter table categoryinfo

ADD CategoryIdvarchar2(10);

--添加主键约束

alter table  production

ADD CONSTRAINTpk_Productionprimary key(ProductId);

alter table  categoryinfo

ADD CONSTRAINT pk_CategoryInfo primary key(CategoryId);

--删除主键约束

alter table categoryinfo

DROP CONSTRAINT pk_CategoryInfo;

--完整练习

create table productioninfo (

Prod uctIdvarchar2(10),

ProductNamevarchar2(20),

ProductPricenumber(8,2),

Quantitynumber(10),

Categoryvarchar2(10),

Desperationvarchar2(1000),

Originvarchar2(10),

primary key(ProductId),

--添加外键

CONSTRAINT fk_pro FOREIGN KEY(Category) REFERENCES categoryinfo(CategoryId) ON DELETE CASCADE

);

alter table productioninfo

DROP CONSTRAINT fk_pro;

--修改添加外键约束

alter table productioninfo

ADD CONSTRAINT fk_pro FOREIGN KEY (Category) REFERENCES categoryinfo(CategoryId)

ON DELETE CASCADE;

select * from categoryinfo;

select * from production;

alter table production

--创建带有check条件的消费者表

create table custominfo(

CustomIdvarchar2(10),

CustomNamevarchar2(20),

CustomAgenumber(2),

Gendervarchar2(2),

Telvarchar2(11),

Addressvarchar2(100),

CONSTRAINT CHK_AGE

CHECK(CustomAge>=18 and CustomAge<=50)

);

--修改时添加check条件

alter table custominfo

ADD CONSTRAINTS chk_gender CHECK(Gender = '男' or Gender = '女');

--删除约束条件

alter table custominfo

DROP CONSTRAINS chk_gender;

--unique约束唯一约束

--订单信息表

create table orderinfo(

OrderIdvarchar2(10),

CustomIdvarchar2(10),

ProductIdvarchar2(10),

OrderDatevarchar2(10),

OrderQuantitynumber(10),

SendDatevarchar2(10),

CONSTRAINTS UNQ_ORDERID UNIQUE(OrderId)

);

--NOT NULL约束

--管理员信息表

create table managerinfo(

ManagerIdvarchar2(10),

LoginNamevarchar2(10) NOT NULL,

Passwordvarchar2(10) NOT NULL,

Namevarchar2(10),

Telnumber(11)

);

--修改notnull约束

alter table managerinfo

MODIFY LoginName Null;