我正在使用 JPA 进行映射，我有这个实体类
@Entity
@Table(name = "h_pe")
@XmlRootElement
@NamedQueries({
public class HPe implements Serializable {
private static final long serialVersionUID = 1L;
@EmbeddedId
protected HPePK hPePK;
@Column(name = "PE_TIMEOUT")
private Integer peTimeout;
@Column(name = "PE_STATUS")
private Boolean peStatus;
@OneToMany(cascade = CascadeType.ALL, mappedBy = "hPe")
private Collection<HPesp> hPespCollection;
@JoinColumn(name = "PE_ENV", referencedColumnName = "ENV_URL", insertable = false, updatable = false)
@ManyToOne(optional = false)
private HEnv hEnv;
@JoinColumn(name = "PE_PLATFORM", referencedColumnName = "PLATFORM_NAME", insertable = false, updatable = false)
@ManyToOne(optional = false)
private HPlatform hPlatform;
}
我想写一个像下面这样的请求JPA(我已经用SQl写了)，我试过写但是我一直不明白如何使用PE_ENV，因为它是OneToMany关系的结果!
select distinct h_env.env_name,h_platform.PLATFORM_NAME
from h_env,h_platform,h_pe
where h_env.ENV_URL=h_pe.PE_ENV
and h_platform.PLATFORM_NAME=h_pe.PE_PLATFORM
and h_platform.PLATFORM_NAME='XXX';
最佳答案
Select e.name, p.name
from HPe hp join hp.hPlatform p join hp.hPespCollection p
where p.name = 'xxx'
看， http://en.wikibooks.org/wiki/Java_Persistence/Querying#Common_Queries
关于java - 在 JPA-SQL 查询中加入集合，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/6774355/