Java 如何正确使用 Hibernate @Index 注释？
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How to use Hibernate @Index annotation properly?
提问by
i have a java class used as an entity that has 2 classes that inherit from it. this class has some indices but these indices didn't appear in the database. this is my java super class code
我有一个用作实体的 java 类，它有 2 个继承自它的类。这个类有一些索引，但这些索引没有出现在数据库中。这是我的 java 超类代码
import java.io.Serializable;
import java.util.List;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.UniqueConstraint;
import javax.persistence.Version;
import javax.persistence.OneToMany;
import org.hibernate.annotations.GenericGenerator;
@Entity
@Table(name="service", uniqueConstraints = {@UniqueConstraint(columnNames={"name"})})
@org.hibernate.annotations.Table(appliesTo = "service",
indexes = { @Index(name = "service_name", columnNames = { "name" }),
@Index(name = "service_description", columnNames = { "description" }),
@Index(name = "service_accessNumber", columnNames = { "access_number" })
})
public class Service implements Serializable {
@Column(name="access_number",length = 95,nullable=false)
String accessNumber;
@Column(length=80,nullable=false)
String name;
@Column(length=140)
String description;
}
does any one know what is my problem Note: i have this problem in my all java classes but this is one of them. the code in all class is the same of this
有谁知道我的问题是什么 注意：我的所有 Java 类都有这个问题，但这是其中之一。所有类中的代码都与此相同
Edit: i build an xml file and put it in a grails project, and when i run this project, database created
编辑：我构建了一个 xml 文件并将其放在一个 grails 项目中，当我运行这个项目时，创建了数据库
采纳答案by Georgian Citizen
i have the same problem, but i found it's solution and it works fine with me try it, it may help you
我有同样的问题，但我找到了它的解决方案，它对我来说很好用试试吧，它可能对你有帮助
in your DataSource.groovy file in your grails project make sure that under
environment dbCreate is not equal to "update": if it is equal to "update", change
it to "create".
This works fine just try it
这很好用，试试吧
回答by Xiè Jìléi
Would a single @Table annotation work? I haven't tried it, I guess the Hibernate @Table might be overridden by JPA @Table.
单个@Table 注释会起作用吗？我还没有尝试过，我猜 Hibernate @Table 可能会被 JPA @Table 覆盖。
You may also try @Index annotation on the column fields:
您也可以在列字段上尝试 @Index 注释：
public class Service implements Serializable {
@Index(name="service_accessnumber")
@Column(name="access_number",length = 95,nullable=false)
String accessNumber;
@Index(name="service_name")
@Column(length=80,nullable=false)
String name;
@Index(name="service_description")
@Column(length=140)
String description;
}
