Java JPA/Hibernate5按序列名称获取序列nextval
如何在Java JPA/Hibernate5按序列名称获取序列nextval,java,hibernate,jpa,sequence,Java,Hibernate,Jpa,Sequence,如何在JPA或hibernate5中通过sequencename获取sequencenextval 我在OracleDB和PostgresqlDB中对以下TEST\u SEQ进行了排序 我需要一个具有以下签名的方法 public Long getSequenceByName(String sequenceName){} 当我调用这个方法时,它必须从现在使用的DB返回nextval 我有一些想法,但不适合 1) 在properties中存储每个DB的本机查询,并按如下方式写入方法: @Value
JPA
或hibernate5
中通过sequencename
获取sequencenextval
我在Oracle
DB和Postgresql
DB中对以下TEST\u SEQ
进行了排序
我需要一个具有以下签名的方法
public Long getSequenceByName(String sequenceName){}
当我调用这个方法时,它必须从现在使用的DB返回nextval
我有一些想法,但不适合
1) 在properties中存储每个DB的本机查询,并按如下方式写入方法:
@Value("${query}")//"SELECT {name}.NEXTVAL FROM DUAL"
private StringQuery;
public Long getSequenceByName(String sequenceName){
uery q = em.createNativeQuery(StringQuery.replace("{name}", sequenceName));
return (java.math.BigDecimal) q.getSingleResult();
}
但我需要用占位符存储查询字符串,并将占位符替换为序列名称,存储每个数据库的查询
2) 创建只有一个字段的实体@Id
。插入实体和getId(序列值)
但如果在不同的数据库中是不同的序列名-
3) 使用。但它适用于Hibernate3,我不知道这是否是一个好方法
编辑:
我尝试以下解决方案:
@Component
public class SequenseRepository {
@PersistenceContext
private EntityManager em;
@Transactional
public Long getID(final String sequenceName) {
final List<Long> ids = new ArrayList<>(1);
Session session = em.unwrap(Session.class);
session.doWork(connection -> {
DialectResolver dialectResolver = new StandardDialectResolver();
Dialect dialect = dialectResolver.resolveDialect((DialectResolutionInfo) connection.getMetaData());
PreparedStatement preparedStatement = null;
ResultSet resultSet = null;
try {
preparedStatement = connection.prepareStatement( dialect.getSequenceNextValString(sequenceName));
resultSet = preparedStatement.executeQuery();
resultSet.next();
ids.add(resultSet.getLong(1));
}catch (SQLException e) {
throw e;
} finally {
if(preparedStatement != null) {
preparedStatement.close();
}
if(resultSet != null) {
resultSet.close();
}
}
});
return ids.get(0);
}
}
多亏了这篇文章,我找到了解决方案 每个数据库的配置和实现:
@Profile("oracle")
@Component("oracleSequenceRepository")
public class OracleSequenceRepository implements SequenceRepository{
private final DataSource dataSource;
@Autowired
public OracleSequenceRepository(@Qualifier("dataSource") DataSource dataSource) {
this.dataSource = dataSource;
}
@Transactional(readOnly = true)
@Override
public int getNext(String sequenceName) {
AbstractSequenceMaxValueIncrementer incr = new OracleSequenceMaxValueIncrementer(this.dataSource, sequenceName);
return incr.nextIntValue();
}
}
及
@aurelius的可能副本你能更仔细地阅读我的问题吗?具体来说,第3点和我提供的链接第3点也显示了hibernate 4的方法。使用方言是一种很好的方法。(至少我们是这样做的,而且效果很好)但我使用hibernate5。感谢您分享有关使用此方法的信息。我还想学习其他方法。
public interface SequenceRepository {
int getNext(String sequenceName);
}
@Profile("oracle")
@Component("oracleSequenceRepository")
public class OracleSequenceRepository implements SequenceRepository{
private final DataSource dataSource;
@Autowired
public OracleSequenceRepository(@Qualifier("dataSource") DataSource dataSource) {
this.dataSource = dataSource;
}
@Transactional(readOnly = true)
@Override
public int getNext(String sequenceName) {
AbstractSequenceMaxValueIncrementer incr = new OracleSequenceMaxValueIncrementer(this.dataSource, sequenceName);
return incr.nextIntValue();
}
}
@Profile("postgre")
@Component("postgresSequenceRepository")
public class PostgreSequenceRepository implements SequenceRepository{
private final DataSource dataSource;
@Autowired
public PostgreSequenceRepository(@Qualifier("dataSource") DataSource dataSource) {
this.dataSource = dataSource;
}
@Transactional(readOnly = true)
@Override
public int getNext(String sequenceName) {
AbstractSequenceMaxValueIncrementer incr = new PostgresSequenceMaxValueIncrementer(this.dataSource, sequenceName);
return incr.nextIntValue();
}
}