ALTER TABLE Doctor ADD CONSTRAINT Doctor_num UNIQUE (Doc_number)
create table Drugs --药品信息
(
Dr_name nvarchar(20) not null,
Dr_number tinyint not null constraint Dr_prim primary key,
Dr_price float not null,
Dr_type nvarchar(10) not null
)
--修改表结构
--删除外键约束
alter table Drugs drop constraint Dr_prim
--更改 Dr_number 数据类型
alter table Drugs
alter column Dr_number nvarchar(10) not null
--添加主键
alter table Drugs add constraint pk_Dr_number primary key(Dr_number)
--添加唯一约束
ALTER TABLE Drugs ADD CONSTRAINT Drugs_num UNIQUE (Dr_number)
create table recipel --处方信息
(
Pat_idcard varchar(18) not null constraint repa_fore foreign key
references Patient(Pat_idcard), --添加外键
Pat_name nvarchar(10) not null,
Doc_number tinyint not null constraint redo_fore foreign key
references Doctor(Doc_number), --添加外键
Dr_number tinyint not null constraint redr_fore foreign key
references Drugs(Dr_number), --添加外键
Dr_name nvarchar(20) not null,
Dr_count tinyint not null,
Total_price float not null,
Stay_hospital nvarchar(5) default '是' not null, --默认约束 是
Sickroom_num tinyint
)
--修改表结构
--更改 Dr_number 数据类型
alter table recipel
alter column Dr_number nvarchar(10) not null
alter table recipel --修改 Sickroom_num 数据类型
alter column Sickroom_num nvarchar(10)
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