[英]Batch insert using Native SQL in Hibernate
我想使用 Hibernate Native SQL 在数据库中插入记录。代码如下
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
String sqlInsert = "insert into sampletbl (name) values (?) ";
for(String name : list){
session.createSQLQuery( sqlInsert )
.setParameter(1,name)
.executeUpdate();
}
tx.commit();
session.close();
上面的代码工作正常。我认为这不是最好的方法。 如果有的话,请给我另一种可能的方法。 谢谢
Hibernate有一个批处理功能。但在上面的例子中,我使用的是Native SQL,根据我的观察,hibernate批处理对于Native SQL来说效果不是很好。是的,它确实避免了内存不足错误,但没有提高性能。 因此我退回到在Hibernate中实现了JDBC doWork()
提供了方法doWork()
来从Hibernate Session获取Connection。
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
//get Connction from Session
session.doWork(new Work() {
@Override
public void execute(Connection conn) throws SQLException {
PreparedStatement pstmt = null;
try{
String sqlInsert = "insert into sampletbl (name) values (?) ";
pstmt = conn.prepareStatement(sqlInsert );
int i=0;
for(String name : list){
pstmt .setString(1, name);
pstmt .addBatch();
//20 : JDBC batch size
if ( i % 20 == 0 ) {
pstmt .executeBatch();
}
i++;
}
pstmt .executeBatch();
}
finally{
pstmt .close();
}
}
});
tx.commit();
session.close();
以下是Java 8,Hibernate-JPA 2.1的相同示例:
@Repository
public class SampleNativeQueryRepository {
private final Logger log = LoggerFactory.getLogger(SampleNativeQueryRepository.class);
@PersistenceContext
private EntityManager em;
public void bulkInsertName(List<String> list){
Session hibernateSession = em.unwrap(Session.class);
String sql = "insert into sampletbl (name) values (:name) ";
hibernateSession.doWork(connection -> {
try (PreparedStatement preparedStatement = connection.prepareStatement(sql)) {
int i = 1;
for(String name : list) {
preparedStatement.setString(1, name);
preparedStatement.addBatch();
//Batch size: 20
if (i % 20 == 0) {
preparedStatement.executeBatch();
}
i++;
}
preparedStatement.executeBatch();
} catch (SQLException e) {
log.error("An exception occurred in SampleNativeQueryRepository.bulkInsertName: {}", e);
}
});
}
}
如果您不需要担心SQL注入。 即,您没有从用户端获取数据,那么您可以这样做。
StringBuilder sqlInsert = new StringBuilder("insert into sampletbl (name) values ");
for(String name : list){
sqlInsert.append("("+name++"),");
}
sqlInsert.setLength(sqlInsert.length() - 1);
session.createSQLQuery( sqlInsert.toString()).executeUpdate();
它会创建一个这样的查询。
insert into sampletbl (name) values ("name1"), ("name2")....
这样,您的查询将只运行一次,而不是列表中的每个项目。
A slight variation leveraging the Named Parameter features of Hibernate Native Query without the Spring JDBC or Spring JPA:
@Transactional(propagation = Propagation.REQUIRED)
public int[] updateInBatch(List<Entity> entities) {
int[] resultsRef = null;
try {
Session session = entityManager.unwrap(Session.class);
int[] results = new int[entities.size()];
IntStream.range(0, entities.size())
.forEach(idx -> {
Entity entity = entities.get(idx);
Query q = session
.createNativeQuery("UPDATE Entity " +
" WHERE " +
" ID = :Id ")
.unwrap(SQLQuery.class)
.setString("Id", entity.getId());
results[idx] = q.executeUpdate();
});
session.flush();
session.clear();
resultsRef = results;
} catch (Exception ex) {
resultsRef = null;
}
return resultsRef;
}
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