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)
);