JPQL SELECT Distinct Query with clob Column 在 WAS7 上工作正常，但 WAS9 不工作

Question

我正在使用 Spring 基于 3.0 的 JPA2.0

@Entity
@Table(name = "MY_TABLE", schema = "DB2XXXX")
public class MyTable  implements java.io.Serializable,Comparable<MyTable> {
    private static final long serialVersionUID = 1L;
    
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name = "MY_TABLE_ID")
    private BigInteger myTableId;
    
    @Column(name = "FREETEXT")
    private String freetext;
    
    public MyTable() {
    }
    
    public MyTable(BigInteger myTableId,String freetext) {
        super();
        this.myTableId = myTableId;
        this.freetext = freetext
    }
    
    public BigInteger getMyTableId() {
        return myTableId;
    }
    public void setMyTableId(myTableId) {
        this.myTableId = myTableId;
    }
    public String getFreetext() {
        return freetext;
    }
    public void setFreetext(String freetext) {
        this.freetext = freetext;
    }
}

freetext 是 clob 列

    public List<MyTable> getData(BigInteger myTableId) throws Exception {
        StringBuilder jpql = new StringBuilder();
        List<MyTable> resultList = null;
        try {
            jpql.append("SELECT distinct data FROM MyTable data ")
            resultList = findWithJpql(entityManager, jpql.toString(), null,false, 0, 0);
        } catch (Exception e) {
        }
        return resultList;
    }

    @TransactionAttribute(value = TransactionAttributeType.REQUIRED)
    @SuppressWarnings("unchecked")
    public <T> T findWithJpql(EntityManager em, String jpql, Map<String, Object> conditions, boolean singleResult, int firstResult, int maxResult) {
        Query query = em.createQuery(jpql);
        if(firstResult > 0){
            query.setFirstResult(firstResult);
        }
        if(maxResult > 0){
            query.setMaxResults(maxResult);
        }

        if(conditions != null && conditions.size() > 0){
            for(String condition : conditions.keySet()){
                query.setParameter(condition, conditions.get(condition));
            }
        }
        if(singleResult){
            try{
                return (T)query.getSingleResult();
            }catch(NoResultException nrex){
                return null;
            }
        }else{
            T a = (T)query.getResultList();
            return a;
        }
    }

在WAS9中调用查询方法时Db2错误代码-134：在同时指定 DISTINCT 的 SELECT 列表中不允许长度属性大于 255 字节的字符串值。 **但是这个查询在 WAS7 上工作正常 **

[21/12/2564，10:28:10:731 ICT] 0000018e eclipselink W 异常 [EclipseLink-4002]（Eclipse 持久性服务 - 2.6.8.WAS-v20181218-0accd7f）：org.eclipse.persistence.exceptions.DatabaseException 内部异常：com.ibm.db2.jcc.am.SqlSyntaxErrorException：DB2 SQL 错误：SQLCODE=-134，SQLSTATE=42907，SQLERRMC=REMARK , 驱动程序=4.25.13 错误代码：-134

内部异常：com.ibm.db2.jcc.am.SqlSyntaxErrorException：DB2 SQL 错误：SQLCODE=-134，SQLSTATE=42907，SQLERRMC=备注，驱动程序=4.25.13 错误代码：-134

Answer 1

如果 freetext 是 Clob 列，请尝试使用 @Lob 对其进行正确注释。检查此 post Using EclipseLink JPA to bind Strings larger than 255 characters .

该错误可能与 WAS7 和 9 之间的 JPA 提供程序更改有关（以前是 OpenJPA）。如果您不关心 JPA 2.1，您可以切换回 2.0 OpenJPA，例如使用 wsadmin:

wsadmin>AdminTask.modifyJPASpecLevel('[-node myNode -server server1 -specLevel 2.0]')  
CWWJP8813I: The JPA specification compliance level for Server server1 has been successfully set to JPA 2.0.

详情见下面link：https://www.ibm.com/docs/en/was/9.0.5?topic=applications-identifying-modifying-jpa-specification-level

JPQL SELECT Distinct Query with clob Column 在 WAS7 上工作正常，但 WAS9 不工作

JPQL SELECT Distinct Query with clob Column works fine on WAS7, but WAS9 doesn't

java

jpa

db2

websphere

jpql