java - 为什么这个序列生成器不在 Spring Boot 中创建数据库表？

Question

@Entity
@Table(name = "addition_type")
public class AdditionType {
    @Id
    @SequenceGenerator(name = "addition_type_id_seq", sequenceName = "addition_type_id_seq", allocationSize = 1)
    @GeneratedValue(strategy = GenerationType.AUTO, generator = "addition_type_id_seq")
    @Column(name = "id")
    private int id;

    @Column(name = "code")
    private String code;

    @Column(name = "name")
    private String name;

    @Column(name = "sinhala_name")
    private String sinhalaName;

    @Column(name = "report_name")
    private String reportName;

    @Column(name = "status")
    private int status;

    @ManyToOne
    @JoinColumn(referencedColumnName = "id")
    private CompanyInfo companyInfo;

    // there are not show getter and setter
}

当我在 Spring 中使用这个类时，生成了两个数据库表:AdditionType实体表，以及 addition_type_id_seq序列生成器对应的表。 AdditionType表有列:id、name、code ...，另一个表有 next value的 id .

当我在 Spring Boot 中使用此类时，它并没有像那样创建两个表。只有 AdditionType表已创建。为什么是SequenceGenerator无法在 Spring Boot 中工作？

Answer 1

由于 MYSQL 方言不支持序列:

我们可以使用表生成器策略来定义序列:

    @Id
    @TableGenerator(name = "addition_type_id_seq", allocationSize = 1, table = "ADDITION_TYPE_SEQUENCES",
                pkColumnName = "SEQ_NAME",
                        valueColumnName = "SEQ_NUMBER",
                pkColumnValue = "SEQUENCE")
    @GeneratedValue(strategy = GenerationType.TABLE, generator = "addition_type_id_seq")
    @Column(name = "id")
    private int id;

这将确保创建两个表:ADDITION_TYPE_SEQUENCES 和 ADDITION_TYPE