在Oracle 10g xe中引用的collumns上设置唯一约束 [英] setting up unique constraint on referenced collumns in oracle 10g xe

问题描述

我有以下情况。

表如下所示：

  CREATE TABLE CompetitionsLanguages（
 competition REF CompetitionType SCOPE IS Competitions，
 language REF LanguageType SCOPE IS Languages 
）; 
  

我需要这个表在（竞争，语言）组合上有一个唯一的约束。
oracle告诉我，我不能在引用其他表的collumns上放一个UNIQUE或PK。

是可以某种方式避免使用CHECK，或某种TRIGGER？

谢谢

解决方案

p> CREATE UNIQUE INDEX unqIndex
ON CompetitionsLanguages（CompetitionsLanguages，CompetitionsLanguages）;


i have the following situation.

table looks like this

CREATE TABLE CompetitionsLanguages (
  competition REF CompetitionType SCOPE IS Competitions,
  language REF LanguageType SCOPE IS Languages
);

i need this table to have a unique constraint on (competition,language) combination. oracle tells me that i cant put a UNIQUE or PK on collumns that reference other tables.

is it possible to somehow avoid the unique, using the CHECK, or some sort of a TRIGGER?

thank you

解决方案

CREATE UNIQUE INDEX unqIndex
    ON CompetitionsLanguages(CompetitionsLanguages, CompetitionsLanguages);

这篇关于在Oracle 10g xe中引用的collumns上设置唯一约束的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！