[oracle]创建表及主外键、唯一性约束

call proc_dropifexists('DDINFO');
create TABLE DDINFO(
DDCODE VARCHAR2(50) NOT NULL,
DDNAME VARCHAR2(50),
CREATEOR VARCHAR2(20),
CREATETIME DATE,
CONSTRAINT UNIQUE_DDCODE UNIQUE(DDCODE),
CONSTRAINT PK_DDCODE PRIMARY KEY(DDCODE)
);
call proc_dropifexists('DDITEMINFO');
CREATE TABLE DDITEMINFO(
DDCODE VARCHAR2(50) NOT NULL,
ITEMCODE VARCHAR2(50) NOT NULL,
ITEMNAME VARCHAR2(50),
CREATETIME DATE,
CONSTRAINT PK_ITEMCODE PRIMARY KEY(ITEMCODE),
CONSTRAINT FK_DDCODE FOREIGN KEY(DDCODE) REFERENCES DDINFO(DDCODE)
);