数据库创表常用约束以及案例参照

①主键 constraint pk_name primary key <column_name>

②外键 constraint fk_name foreign key(column_name) reference table_name(column_name)

③检查 constraint ck_name check (condition)

④唯一 constraint un_name unique (column_name)

⑤非空 <column name> <data type> not null,

⑥默认值<column name> <data type> default <default value>,

--创建占台表
create table T_STATION
(
TRAINNUM VARCHAR2(50), --火车编号
STARTSTATION VARCHAR2(50), --初始占台
ENDSTATION VARCHAR2(50), --结束站
STARTTIME VARCHAR2(50), --开始时间
ENDTIME VARCHAR2(50), --结束时间
TOTALTIME VARCHAR2(50), --总的时长
PRICE FLOAT, --价格
OBJ VARCHAR2(100), --备注
constraint fk_TRAINNUM foreign key (TRAINNUM) references T_TRAIN(TRAINNUM) --约束外键-关联火车表 -
)

create table T_SEAT
(
TRAINNUM VARCHAR2(50),
SEATTYPE VARCHAR2(50),
SEATNO VARCHAR2(50),
SEATPRICE FLOAT,
SEATSTATU INTEGER,
OBJ VARCHAR2(100),
constraint t_fk_TRAINNUM foreign key (TRAINNUM) references T_TRAIN(TRAINNUM) --约束外键-关联火车表 -
)

--创建订单表
create table T_ORDER
(
ONUMBER VARCHAR2(50) primary key,
TRAINNUM VARCHAR2(50),
STARTTIME VARCHAR2(50),
ENDTIME VARCHAR2(50),
PRICE FLOAT,
SEATNO VARCHAR2(50),
SEATTYPE VARCHAR2(20),
USERNAME VARCHAR2(50),
PHONENUMBER VARCHAR2(30),
IDCARD VARCHAR2(50),
EMAIL VARCHAR2(50),
OBJ VARCHAR2(100),
constraint o_fk_TRAINNUM foreign key (TRAINNUM) references T_TRAIN(TRAINNUM) --约束外键-关联火车表 -
)

create table T_USERINFO
(
USERNAME VARCHAR2(50),
ADDRESS VARCHAR2(100),
EMAIL VARCHAR2(50),
PHONENUMBER VARCHAR2(30),
IDCARD VARCHAR2(50),
OBJ VARCHAR2(100)
)

--火车优惠
create table t_favorable
(
TRAINNUM VARCHAR2(50),--火车编号
STARTTIME VARCHAR2(50), --开始时间
ENDTIME VARCHAR2(50), --结束时间
discount float, --优惠折扣
price float, --优惠价格
OBJ VARCHAR2(100),--备注
constraint f_fk_TRAINNUM foreign key (TRAINNUM) references T_TRAIN(TRAINNUM) --约束外键-关联火车表 -
)