从表中选择特定列，然后使用Spring + hibernate + JPA将结果存储到非实体POJO

Question

I am using Spring 3.1.3 + hibernate-entitymanager 5.0.7 (Which contains JPA of version 2.1 ) + ojdbc14-10.2.0.2.jar

I want to select specific columns from the table and store the results to the non-entity POJO. I want to implement in the way how it is proposed in below link

Spring Data JPA map the result to Non-Entity POJO

My Entity class:

   @Entity
    @Data
    @Table(name = "CUSTOMER")
    @SqlResultSetMapping(name="SampleMapping",
    classes = {
     @ConstructorResult(targetClass = com.entity.Sample.class,
       columns = {@ColumnResult(name="customerId"), @ColumnResult(name="name"), @ColumnResult(name="firstName")}
     )}
    )
    public class CustomerEntity {

        @Id
        @Column(name = "CUSTOMER_ID")
        private String customerId;

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

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

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

       @Column(name = "AGE")
        private String age;
    }

My Query Part:

String q = "select s.customerId, s.name, s.firstName from CustomerEntity s";
Query query = entityManager.createNativeQuery(q,"SampleMapping");
List<Sample> resultsList = query.getResultSet();

Sample class is simple POJO (with parameterized constructor with customerId, name and firstName) where i want to store my results of query.

Can you please advise me which versions of Spring, Hibernate, JPA, ojdbc jars I need to add in order to achieve my requirement? Many thanks in advance.

Couldn't idendify if the below exception is because of versions of jar or any incorrect declaration of annotations or query format.

Because I face few exceptions when I add the below jars:

    +- com.commons:commons-dao:jar:1.0## Heading ##-SNAPSHOT:compile
    |  +- oracle:ojdbc14:jar:10.2.0.2:compile
    |  +- org.springframework:spring-tx:jar:3.1.3.RELEASE:compile
    |  |  +- aopalliance:aopalliance:jar:1.0:compile
    |  |  \- org.springframework:spring-core:jar:3.1.3.RELEASE:compile
    |  +- org.springframework:spring-orm:jar:3.1.3.RELEASE:compile
    |  |  \- org.springframework:spring-jdbc:jar:3.1.3.RELEASE:compile
    |  +- org.hibernate:hibernate-entitymanager:jar:5.0.7.Final:compile
    |  |  +- org.hibernate:hibernate-core:jar:5.0.7.Final:compile
    |  |  |  +- antlr:antlr:jar:2.7.7:compile
    |  |  |  \- org.jboss:jandex:jar:2.0.0.Final:compile
    |  |  +- dom4j:dom4j:jar:1.6.1:compile
    |  |  +- org.hibernate.common:hibernate-commons-annotations:jar:5.0.1.Final:compile
    |  |  +- org.hibernate.javax.persistence:hibernate-jpa-2.1-api:jar:1.0.0.Final:compile
    |  |  \- org.apache.geronimo.specs:geronimo-jta_1.1_spec:jar:1.1.1:compile
    |  +- org.javassist:javassist:jar:3.14.0-GA:compile
    |  +- javax.resource:connector:jar:1.0:compile
    |  |  +- org.springframework:spring-oxm:jar:3.1.3.RELEASE:compile
    |  |     \- org.apache.httpcomponents:httpclient-cache:jar:4.2.4:compile
    |  +- org.springframework:spring-beans:jar:3.1.3.RELEASE:compile (version managed from 3.1.2.RELEASE)
    |  +- org.springframework:spring-context:jar:3.1.3.RELEASE:compile (version managed from 3.1.2.RELEASE)
    |  |  +- org.springframework:spring-expression:jar:3.1.3.RELEASE:compile
    |  |  \- org.springframework:spring-asm:jar:3.1.3.RELEASE:compile
    |  +- org.slf4j:jcl-over-slf4j:jar:1.6.4:runtime
    |  \- org.slf4j:log4j-over-slf4j:jar:1.6.4:runtime
    |  +- org.springframework:spring-webmvc:jar:3.1.3.RELEASE:compile
    |  |  \- org.springframework:spring-context-support:jar:3.1.3.RELEASE:compile
    |  +- org.springframework:spring-web:jar:3.1.3.RELEASE:compile
    |  +- org.springframework:spring-aop:jar:3.1.3.RELEASE:compile
    |  +- org.springframework.integration:spring-integration-core:jar:2.2.6.RELEASE:compile
    |  |  \- org.springframework.retry:spring-retry:jar:1.0.2.RELEASE:compile
    |  +- org.springframework.integration:spring-integration-event:jar:2.2.6.RELEASE:runtime
    |  +- org.springframework.integration:spring-integration-file:jar:2.2.6.RELEASE:runtime
    |  +- org.springframework.integration:spring-integration-http:jar:2.2.6.RELEASE:compile
    |  +- org.springframework.integration:spring-integration-xml:jar:2.2.6.RELEASE:compile
    |  |  \- org.springframework.ws:spring-xml:jar:2.1.1.RELEASE:compile
    |  +- org.springframework.integration:spring-integration-jms:jar:2.2.6.RELEASE:compile
    |  |  \- org.springframework:spring-jms:jar:3.1.3.RELEASE:compile
    |  +- org.springframework.integration:spring-integration-ws:jar:2.2.6.RELEASE:compile
    |  |  \- org.springframework.ws:spring-ws-core:jar:2.1.1.RELEASE:compile
    +- org.hibernate:hibernate-validator:jar:4.3.0.Final:compile
    +- log4j:log4j:jar:1.2.17:provided
    +- org.slf4j:slf4j-api:jar:1.7.12:compile
    +- org.jboss.logging:jboss-logging:jar:3.3.0.Final:compile
    \- org.slf4j:slf4j-simple:jar:1.7.12:compile

But I got resulted in below exception in the below line

List<Sample> resultsList = query.getResultSet();

Exception:

 org.springframework.dao.InvalidDataAccessResourceUsageException: could not extract ResultSet; SQL [n/a]; nested exception is org.hibernate.exception.SQLGrammarException: could not extract ResultSet
           at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:635) ~[spring-orm-3.1.3.RELEASE.jar:3.1.3.RELEASE]
           at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:104) ~[spring-orm-3.1.3.RELEASE.jar:3.1.3.RELEASE]
           at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:403) ~[spring-orm-3.1.3.RELEASE.jar:3.1.3.RELEASE]
           at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:58) ~[spring-tx-3.1.3.RELEASE.jar:3.1.3.RELEASE]
           at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:213) ~[spring-tx-3.1.3.RELEASE.jar:3.1.3.RELEASE]
           at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:163) ~[spring-tx-3.1.3.RELEASE.jar:3.1.3.RELEASE]
           at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172) ~[spring-aop-3.1.3.RELEASE.jar:3.1.3.RELEASE]
           at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202) ~[spring-aop-3.1.3.RELEASE.jar:3.1.3.RELEASE]
           at com.common.dao.SampleServiceImpl.sampleMethod(SrvImplemet.java:123) ~[commons-dao-1.0-SNAPSHOT.jar:na]

      Caused by: org.hibernate.exception.SQLGrammarException: could not extract ResultSet
           at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:106) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:109) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:95) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:79) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.loader.Loader.getResultSet(Loader.java:2116) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1899) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1875) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.loader.Loader.doQuery(Loader.java:919) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:336) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.loader.Loader.doList(Loader.java:2611) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.loader.Loader.doList(Loader.java:2594) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2423) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.loader.Loader.list(Loader.java:2418) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.loader.custom.CustomLoader.list(CustomLoader.java:336) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.internal.SessionImpl.listCustomQuery(SessionImpl.java:1967) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.internal.AbstractSessionImpl.list(AbstractSessionImpl.java:322) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.internal.SQLQueryImpl.list(SQLQueryImpl.java:125) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.jpa.internal.QueryImpl.list(QueryImpl.java:606) ~[hibernate-entitymanager-5.0.7.Final.jar:5.0.7.Final]
           at org.hibernate.jpa.internal.QueryImpl.getResultList(QueryImpl.java:483) ~[hibernate-entitymanager-5.0.7.Final.jar:5.0.7.Final]
           at com.common.dao.SampleDaompl.sampleMethod.SampleDaoImpl.getData(SampleDaoImpl.java:16) ~[commons-dao-1.0-SNAPSHOT.jar:na]
           at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.7.0_51]
           at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) ~[na:1.7.0_51]
           at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.7.0_51]
           at java.lang.reflect.Method.invoke(Method.java:606) ~[na:1.7.0_51]
           at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:319) ~[spring-aop-3.1.3.RELEASE.jar:3.1.3.RELEASE]
           at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183) ~[spring-aop-3.1.3.RELEASE.jar:3.1.3.RELEASE]
           at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150) ~[spring-aop-3.1.3.RELEASE.jar:3.1.3.RELEASE]
           at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:155) ~[spring-tx-3.1.3.RELEASE.jar:3.1.3.RELEASE]
           ... 191 common frames omitted
    Caused by: java.sql.SQLException: ORA-00942: table or view does not exist

           at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112) ~[ojdbc14-10.2.0.2.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
           at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:331) ~[ojdbc14-10.2.0.2.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
           at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:288) ~[ojdbc14-10.2.0.2.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
           at oracle.jdbc.driver.T4C8Oall.receive(T4C8Oall.java:743) ~[ojdbc14-10.2.0.2.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
           at oracle.jdbc.driver.T4CPreparedStatement.doOall8(T4CPreparedStatement.java:216) ~[ojdbc14-10.2.0.2.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
           at oracle.jdbc.driver.T4CPreparedStatement.executeForDescribe(T4CPreparedStatement.java:799) ~[ojdbc14-10.2.0.2.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
           at oracle.jdbc.driver.OracleStatement.executeMaybeDescribe(OracleStatement.java:1039) ~[ojdbc14-10.2.0.2.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
           at oracle.jdbc.driver.T4CPreparedStatement.executeMaybeDescribe(T4CPreparedStatement.java:839) ~[ojdbc14-10.2.0.2.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
           at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:1132) ~[ojdbc14-10.2.0.2.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
           at oracle.jdbc.driver.OraclePreparedStatement.executeInternal(OraclePreparedStatement.java:3285) ~[ojdbc14-10.2.0.2.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
           at oracle.jdbc.driver.OraclePreparedStatement.executeQuery(OraclePreparedStatement.java:3329) ~[ojdbc14-10.2.0.2.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
           at org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:93) ~[commons-dbcp-1.2.2.jar:1.2.2]
           at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:70) ~[hibernate-core-5.0.7.Final.jar:5.0.7.Final]
           ... 215 common frames omitted

Note: previously when I had tried to select all rows and storing the results to Entity class with the dependencies Spring 3.1.3 + hibernate-entitymanager 3.5.3 + JPA 2.0 + ojdbc14-10.2.0.2.jar, I was able to fetch the results succesfully without any exception.

Differences :

1. jar version hibernate-entitymanager 3.5.3 & JPA of version 2.0
2. Query was select * ..
3. Entity class without the @SqlResultSetMapping annotation

Answer 1

If I understand you question correctly you have an existing table with the following columns

• name, firstName, lastName, age (possible more columns)

And you want to create an entity so you can get data from that table.

The first thing to note is that all JPA Entities MUST have a primary key (@ID column). Second, I have never had to use @SqlResultSetMapping for this to work.

In our system we have a View that is mappe directly to an entity, there is no difference between this entity and any other entities in our system, if you didn't look in the database you would not know that there is no table (but a view) for this entity.

Edit I can see I missed part of the question. So here is what I thik you asked for.

You need to look a JPQL Constructor Expression it basically allows you to select the columns you want into a POJO of your choice, but the constructor of the POJO must be able to the exact list of arguments.

Answer 2

you can use criteria and projections

Criteria query = session.createCriteria(CustomerEntity.class)
    .setProjection(Projections.projectionList()
                .add(Projections.property("customerId"), "customerId")
                .add(Projections.property("name"), "name")
                .add(Projections.property("firstName"), "firstName"));

query.setResultTransformer(new AliasToBeanResultTransformer(Sample.class));

List<Sample> list = query.list();

the Sample class

public class Sample {

    private String customerId;
    private String name;
    private String firstName;

    public Sample(){
    }

    public String getCustomerId() {
        return customerId;
    }
    public void setCustomerId(String customerId) {
        this.customerId = customerId;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getFirstName() {
        return firstName;
    }
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }


}

Answer 3

Here is how you can do it:

List<Sample> resultList = new ArrayList<>();
ResultSet rs = query.getResultSet();

while (rs.next()) {
    ResultSetMetaData metadata = rs.getMetaData();

    for (int i = 1; i <= metadata.getColumnCount(); i++) {
        System.out.println("Column Name: " + metadata.getColumnName(i)
                + " | Value: " + rs.getObject(i));
    }

    Sample sample = new Sample();
    sample.setSomeValue(rs.getObject(1));
    sample.setSomeOtherValue(rs.getObject(2));

    resultList.add(sample);
}

Please note that here the use of ResultSetMetaData is optional. I have used it just to show how you can extract the Column Names if you want.

Answer 4

Here's one way to do it.

@Entity
@Table(name = "CUSTOMER")
@NamedNativeQuery(name = "findSampleMapping", 
    query = "SELECT CUSTOMER_ID, NAME, FIRST_NAME FROM CUSTOMER where CUSTOMER_ID = ?1", resultSetMapping = "SampleMapping")
@SqlResultSetMapping(name="SampleMapping",
classes = {
 @ConstructorResult(targetClass = com.entity.Sample.class,
   columns = {@ColumnResult(name="customerId"), @ColumnResult(name="name"), @ColumnResult(name="firstName")}
 )}
)
public class CustomerEntity {

    @Id
    @Column(name = "CUSTOMER_ID")
    private String customerId;

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

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

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

   @Column(name = "AGE")
    private String age;
}



public class Sample {


    private String customerId;
    private String name;
    private String firstName;

    public Sample(String customerId, String name, String firstName){
        this.customerId = customerId;
        this.name = name;
        this.firstName = firstName;
    }

    public String getCustomerId() {
        return customerId;
    }
    public void setCustomerId(String customerId) {
        this.customerId = customerId;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getFirstName() {
        return firstName;
    }
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }


}



Query q = em.createNamedQuery("findSampleMapping");
q.setParameter(1, "1");
@SuppressWarnings("unchecked")
List<Sample> list = q.getResultList();
for (Sample row : list) {
    System.out.println(row.getCustomerId());
}