我有两个表,其中一个是ESERVICE,另一个是WORKFLOW,eservice有一个工作流ID作为外键。并非所有eservices都有工作流程,所以我想在存在时获取工作流程名称,否则空值或空值对我来说很好。
所以我写了如下的sql,这对我来说很好。 (用oracle测试)
SELECT e.EE_ESERVICE_ID,
CASE
WHEN EXISTS
(SELECT 1
FROM WORKFLOWS w
WHERE w.WORKFLOW_ID = e.WORKFLOW_ID)
THEN
(SELECT i.I18ND_TRANSLATION
FROM WORKFLOWS w, I18N_DICTIONARY i
WHERE WORKFLOW_ID = e.WORKFLOW_ID
AND i.I18N_ID = w.WORKFLOW_NAME
AND i.I18N_LOCALE_ID = 1)
ELSE
COALESCE ('', '')
END
AS WORKFLOW_NAME
FROM ESERVICES e
现在我需要将其转换为hql,所以我写为
StringBuffer hql = new StringBuffer("select e.eserviceId as eserviceId,"
+ " (case when exists(select 1 from Workflow w where w.workflowId = e.workflowId)"
+ " then (select i.i18ndTranslation from Workflow w,I18nDictionary i where w.workflowId = e.workflowId and i.i18nId = w.workflowName and i.i18nLocaleId = :localeId)"
+ " else coalesce('', '') end) as workflowName"
+ " from Eservice as e");
但是当我使用它时,我得到 org.hibernate.hql.internal.ast.QuerySyntaxException:意外的AST节点
我知道我们可以直接从左连接实现它,但由于一些限制,我们使用交叉连接,所以我需要这样...
请分享您的想法欢迎提出建议
更新1 我们没有使用关联,这就是我们严格交叉加入的原因。
Eservice.java
@Entity
@Table(name = "ESERVICES")
public class Eservice implements java.io.Serializable {
private static final long serialVersionUID = -4088905661029802626L;
public Eservice() {}
@Id
@SequenceGenerator(name = "escSequence", sequenceName = "SQ_ESERVICES",allocationSize=1)
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "escSequence")
@Column(name = "EE_ESERVICE_ID", unique = true, nullable = false)
private BigDecimal eserviceId;
@Column(name = "WORKFLOW_ID")
private BigDecimal workflowId;
@Transient
private String workflowName;
// setter and getter
}
Workflow.java
@Entity
@Table(name = "WORKFLOWS")
public class Workflow implements java.io.Serializable {
private static final long serialVersionUID = -4863237070153860617L;
public Workflow() {}
@Id
@SequenceGenerator(name = "wfSequence", sequenceName="SQ_WORKFLOWS", allocationSize=1)
@GeneratedValue(strategy=GenerationType.SEQUENCE , generator = "wfSequence")
@Column(name = "WORKFLOW_ID", unique = true, nullable = false)
private BigDecimal workflowId;
@Column(name = "I18N_WORKFLOW_NAME")
private BigDecimal workflowName;
// setter and getter
}
I18nDictionary.java
@Entity
@Table(name="I18N_DICTIONARY")
@Cache(usage=CacheConcurrencyStrategy.READ_WRITE)
public class I18nDictionary implements Serializable{
/**
* The serialization runtime associates with each serializable class a version number called serialVersionUID.
*/
private static final long serialVersionUID = -2587075034303056842L;
@Id
@SequenceGenerator(name = "seqDictGenerator", sequenceName = "SQ_I18N_DICTIONARY",allocationSize=1)
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "seqDictGenerator")
@Column(name="I18N_DICT_ID", unique = true, nullable = false)
private BigDecimal i18nDictId;
@Column(name="I18N_ID")
private BigDecimal i18nId;
@Column(name="I18ND_TRANSLATION")
private String i18ndTranslation;
@Column(name="I18N_LOCALE_ID")
private BigDecimal i18nLocaleId;
// setter and getter
}
EserviceHibDAO.java
Query query = getSession()
.createQuery(hql.toString().trim())
.setBigDecimal("localeId", i18nLocale.getI18nLocaleId())
.setResultTransformer(Transformers.aliasToBean(Eservice.class));
List<Eservice> resultSet = query.list();
答案 0 :(得分:0)
对我来说,你可以试试这个:
select e.eserviceId as eserviceId,
case
when e.workflowId is null then ''
else
(select i.i18ndTranslation from Workflow w,I18nDictionary i
where w.workflowId = e.workflowId
and i.i18nId = w.workflowName and i.i18nLocaleId = :localeId)
end as workflowName
from Eservice as e
修改强>
试试这个:
您的查询将变为:
String hql =
"select " + new Eservice.class.getName() +
"(e.eserviceId, " +
"case " +
" when e.workflowId is null then '' " +
" else " +
" (select i.i18ndTranslation from Workflow w,I18nDictionary i " +
" where w.workflowId = e.workflowId " +
" and i.i18nId = w.workflowName and i.i18nLocaleId = :localeId) " +
"end)" +
" from Eservice as e "
在您的Eservice类中,您必须定义一个合适的构造函数,如下所示:
public Eservice(BigDecimal eserviceId, String workflowName) {
this.eserviceId = eserviceId;
this.workflowName = workflowName;
}
最后,您的检索代码将变为:
Query query = getSession().createQuery(hql.toString().trim())
.setBigDecimal("localeId", i18nLocale.getI18nLocaleId());
List<Eservice> resultSet = (List<Eservice>)query.list();