Hibernate，liquibase和hsqldb的Id生成问题 [英] Id generation issue with Hibernate, liquibase and hsqldb

问题描述

我使用liquibase创建了一个表：

I've created a table using liquibase:

<createTable tableName="employees">
    <column name="id" type="bigint">
        <constraints primaryKey="true" nullable="false"/>
    </column>
    <column name="name" type="varchar(50)">
        <constraints nullable="false"/>
    </column>
</createTable>

生成以下sql ddl查询：

The following sql ddl query is generated:

CREATE TABLE employees (id BIGINT NOT NULL, name VARCHAR(50) NOT NULL, CONSTRAINT PK_EMPLOYEES PRIMARY KEY (id));

相应的实体：

@Entity
@Table(name="employees")
public class EmployeeAccessProperty ...
    @Id
    @GeneratedValue
    public long getId() {
        return id;
    }
...

现在，当我尝试通过JPA实现，生成sql查询以插入数据：

Now, when I try to save it via JPA implementation, the sql query is generated to insert data:

Hibernate: insert into employees (id, name) values (default, ?)
2013-05-20T14:29:22.525+0700  WARN  SQL Error: -5544, SQLState: 42544
2013-05-20T14:29:22.526+0700  ERROR  DEFAULT keyword cannot be used as column has no DEFAULT

我预计，当我没有指定id生成策略时，Hibernate会选择最好的一个根据提供商。我不明白为什么ID生成尝试使用默认值。我不确定，哪一方负责错误：hibernate，liqubase或hsqldb。

I expected, that when I don't specify id generation strategy, Hibernate will choose the best one according to the provider. I don't understand why for ID generation the default value is tried to be used. I'm not sure, which side is responsible for the error: hibernate, liqubase or hsqldb.

我该怎么办才能解决这个问题？请帮助我。

What can I do to resolve the problem? Please help me.

推荐答案

您没有告诉您的数据库您的主键必须自动生成。以这种方式创建表：

You are not telling to your database that your primary key must be autogenerated. Create your table this way :

CREATE TABLE employees (id BIGINT GENERATED BY DEFAULT AS IDENTITY, name VARCHAR(50) NOT NULL, CONSTRAINT PK_EMPLOYEES PRIMARY KEY (id));

这篇关于Hibernate，liquibase和hsqldb的Id生成问题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！