这个blog其实是对于IDA的建模的一个疑问，以后有了明确的答案以后，需要补充
看表ORDER_DETAILS的外键关系
SELECT TBNAME,
       RELNAME,
       REFTBNAME,
       DELETERULE,
       UPDATERULE,
       FKCOLNAMES,
       PKCOLNAMES,
       REFKEYNAME
  FROM SYSIBM.SYSRELS
 WHERE CREATOR = 'GOSALES' AND TBNAME = 'ORDER_DETAILS'
  WITH UR;






从DDL的方面看
ALTER TABLE "GOSALES"."ORDER_DETAILS"
  ADD CONSTRAINT "FK_6447247" FOREIGN KEY
    ("ORDER_NUMBER")
  REFERENCES "GOSALES"."ORDER_HEADER"
    ("ORDER_NUMBER")
    ON DELETE NO ACTION
    ON UPDATE NO ACTION
    ENFORCED
    ENABLE QUERY OPTIMIZATION;

ALTER TABLE "GOSALES"."ORDER_DETAILS"
  ADD CONSTRAINT "FK_22447304" FOREIGN KEY
    ("PRODUCT_NUMBER")
  REFERENCES "GOSALES"."PRODUCT"
    ("PRODUCT_NUMBER")
    ON DELETE NO ACTION
    ON UPDATE NO ACTION
    ENFORCED
    ENABLE QUERY OPTIMIZATION;

定义方式基本一样
但是从IDA生成的Physical data model看，是有区别的




这里难以理解mandatory和Optional是怎么产生的。详细订单记录应该是必须有产品和订单头的信息的吧。