如何在JDL-Studio中为2列创建唯一约束? [英] How to create unique constraint for 2 columns in JDL-Studio?

问题描述

我具有以下实体配置:

entity AirplaneModelSeat { 
    id Long, 
    seatNo String required 
}
relationship ManyToOne   { 
    AirplaneModelSeat{modelId(model)} to AirplaneModel 
}

此实体配置创建了这样一个表:

This entity configuration creates such a table:

+-------------+--------------+------+-----+---------+----------------+
| Field       | Type         | Null | Key | Default | Extra          |
+-------------+--------------+------+-----+---------+----------------+
| id          | bigint(20)   | NO   | PRI | NULL    | auto_increment |
| seat_no     | varchar(255) | NO   |     | NULL    |                |
| model_id_id | bigint(20)   | YES  | MUL | NULL    |                |
+-------------+--------------+------+-----+---------+----------------+

如何在JDL-Studio中为(seat_no，model_id_id)列组合应用唯一约束?

How can I apply unique constraint for (seat_no, model_id_id) column combination in JDL-Studio?

如果在JDL-Studioi中无法做到这一点，还有其他方法可以做到吗?

If this is not possible in JDL-Studioi is there any other to accomplish this?

推荐答案

据我所知，约束不是一般情况下JDL的一部分.您可以定义诸如验证之类的东西.但是对于域，唯一约束不再那么笼统，它是数据库级别的约束，必须在其中应用.

As far as I know, constraints are not part of JDL in a general manner. You can define such things as validations. But as for the Domain, the unique constraint is not that general anymore, it is a database level constraint, where it has to be applied.

为此，JHipster包括Liquibase.因此，您可以找到更改日志，在"src/main/resources/config/liquibase"中定义实体约束，然后添加

For this, JHipster includes Liquibase. So you can find the changelog, defining the entity constraints in "src/main/resources/config/liquibase", and add a

<addUniqueConstraint tableName="airplane_model_seat" columnNames="seat_no, model_id_id"/>

更改日志.

如果您已经使用h2磁盘持久性数据库启动了应用程序，请先mvn clean/./gradlew clean，然后再重新启动应用程序.

If you already started your application used h2 disk persistent databse, make a mvn clean / ./gradlew clean before starting your app again.

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