集合的唯一约束< String>与休眠 [英] Unique Constraint for Set<String> with Hibernate

问题描述

  @ElementCollection 
 Set< String>< p> ;分支机构; 
  

现在Hibernate正在创建一个表 project_branches （project_id | branches）并在分支上添加唯一约束。有什么办法可以告诉hibernate：唯一约束应该包含 project_id 和 分支？

我找不到这个问题的答案，但我认为我不是第一个有这个问题的答案......谢谢

解决方案

这取决于映射中涉及的列。

还有另一种配置。请考虑在实体级别添加 UniqueConstraint 注释，例如如下：

  @Table（name =project_branches，
 uniqueConstraints = {@UniqueConstraint（columnNames = {project_id ，branches}）} 
）
  

编辑：尝试使用 @CollectionTable 注释。

  @ElementCollection 
 @CollectionTable（
 name =project_branches，
 joinColumns = @ JoinColumn（name =branches），
 uniqueConstraints = {@UniqueConstraint（columnNames = {project_id，branches}} ）} 
）
 Set< String>分支机构; 
  

I'm having an Entity that contains a Set like the following:

@ElementCollection
Set<String> branches;

Now what Hibernate does, is creating a table project_branches (project_id | branches) and adding a unique constraint on branches. Is there any way to tell hibernate that the unique constraint should involve both, project_id and branches?

I could not find an answer to this question, though I think I'm not the first with this problem... Thanks

解决方案

This is dependent on the columns involved in the mapping.

There in one other configuration. Please consider adding an UniqueConstraint annotation at entity level e.g. below:

  @Table(name="project_branches",
    uniqueConstraints = {@UniqueConstraint(columnNames={"project_id", "branches"})}
  )

EDIT: Try using @CollectionTable annotation.

 @ElementCollection
 @CollectionTable(
    name="project_branches",
    joinColumns=@JoinColumn(name="branches"),
    uniqueConstraints = {@UniqueConstraint(columnNames={"project_id", "branches"})}
  )
  Set<String> branches;

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