jpa可以使用insert into select

语句吗？

是的，JPA可以使用insert into select语句。JPA提供了一些API和注解，可以方便地将查询结果映射到实体类中并插入到数据库中。您可以通过使用@Query注解或Criteria API等方式执行自定义的insert select查询。请注意，在执行此操作时，确保您已正确设置实体类和数据库表之间的映射关系，以及使用正确的事务和锁定机制来保证数据的一致性和完整性。

相关问题

Long id = billingWaterDTO.getBrokerEnterprise().getId(); StringBuilder sqlBuilder = new StringBuilder(); sqlBuilder.append("insert into billingwater (balance,billDate,feeType,iOFlag,iOmoney,remake,brokerEnterpriseFeeId) "); sqlBuilder.append("VALUES ("); sqlBuilder.append("(Select t.balance from "); sqlBuilder.append("(select balance"); sqlBuilder.append("-"); sqlBuilder.append(billingWaterDTO.getiOmoney()); sqlBuilder.append(" as balance from billingwater where brokerEnterpriseFeeId="); sqlBuilder.append(id); sqlBuilder.append(" ORDER BY id desc limit 0,1) t), "); if (billingWaterDTO.getBillDate() == null) { sqlBuilder.append("NOW(),'"); } else { sqlBuilder.append("'"); sqlBuilder.append(DateFormatUtils.format(billingWaterDTO.getBillDate(), DateUtil.DATE_TIME)); sqlBuilder.append("','"); } sqlBuilder.append(billingWaterDTO.getFeeType()); sqlBuilder.append("','"); sqlBuilder.append(billingWaterDTO.getiOFlag()); sqlBuilder.append("','"); sqlBuilder.append(billingWaterDTO.getiOmoney()); sqlBuilder.append("','"); sqlBuilder.append(billingWaterDTO.getRemake()); sqlBuilder.append("','"); sqlBuilder.append(id); sqlBuilder.append("')"); 改成jpa

可以使用JPA的EntityManager来进行插入操作，首先需要在实体类上添加@Entity注解，并且在实体类中添加对应的属性和getter/setter方法。例如，假设实体类为BillingWater：

@Entity
@Table(name = "billingwater")
public class BillingWater {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    private BigDecimal balance;
    
    @Column(name = "billDate")
    private Date billDate;
    
    @Column(name = "feeType")
    private String feeType;
    
    @Column(name = "iOFlag")
    private String iOFlag;
    
    @Column(name = "iOmoney")
    private BigDecimal iOmoney;
    
    private String remake;
    
    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "brokerEnterpriseFeeId")
    private BrokerEnterprise brokerEnterprise;

    // 省略getter/setter方法
}

然后可以在对应的Repository中定义插入方法，例如：

public interface BillingWaterRepository extends JpaRepository<BillingWater, Long> {

    @Modifying
    @Query(value = "insert into billingwater (balance,billDate,feeType,iOFlag,iOmoney,remake,brokerEnterpriseFeeId) " +
                   "VALUES (:balance, :billDate, :feeType, :iOFlag, :iOmoney, :remake, :brokerEnterpriseFeeId)", nativeQuery = true)
    void insertBillingWater(@Param("balance") BigDecimal balance,
                            @Param("billDate") Date billDate,
                            @Param("feeType") String feeType,
                            @Param("iOFlag") String iOFlag,
                            @Param("iOmoney") BigDecimal iOmoney,
                            @Param("remake") String remake,
                            @Param("brokerEnterpriseFeeId") Long brokerEnterpriseFeeId);
}

然后在插入之前可以判断字段是否为空，例如：

if(StringUtils.isNotBlank(billingWaterDTO.getBrokerEnterprise().getId().toString())
   && StringUtils.isNotBlank(billingWaterDTO.getFeeType())
   && StringUtils.isNotBlank(billingWaterDTO.getiOFlag())
   && billingWaterDTO.getiOmoney() != null) {
       // 执行插入操作
       BillingWater billingWater = new BillingWater();
       BigDecimal balance = entityManager.createNativeQuery("select balance - :iOmoney as balance from billingwater where brokerEnterpriseFeeId = :id order by id desc limit 0,1")
                                           .setParameter("iOmoney", billingWaterDTO.getiOmoney())
                                           .setParameter("id", billingWaterDTO.getBrokerEnterprise().getId())
                                           .getSingleResult();
       billingWater.setBalance(balance);
       billingWater.setFeeType(billingWaterDTO.getFeeType());
       billingWater.setiOFlag(billingWaterDTO.getiOFlag());
       billingWater.setiOmoney(billingWaterDTO.getiOmoney());
       billingWater.setRemake(billingWaterDTO.getRemake());
       billingWater.setBrokerEnterprise(brokerEnterpriseRepository.findById(billingWaterDTO.getBrokerEnterprise().getId()).orElse(null));
       if (billingWaterDTO.getBillDate() == null) {
           billingWater.setBillDate(new Date());
       } else {
           billingWater.setBillDate(billingWaterDTO.getBillDate());
       }
       billingWaterRepository.save(billingWater);
}

其中，使用EntityManager的createNativeQuery()方法执行原生SQL查询，然后获取查询结果并设置到实体类中，最后使用JpaRepository的save()方法进行保存操作。

需要注意的是，在使用JpaRepository进行插入操作时，需要在对应的方法上添加@Modifying注解和@Query注解，并且将nativeQuery属性设置为true，表示使用原生SQL语句进行操作。同时，在设置参数时需要使用@Param注解来指定参数的名称。

给我写一个jpa的增删改查代码

答：public class JPATest {
public static void main(String[] args) {
// 增加
String sql = "insert into tableName (field1, field2) values(?, ?)";
Object[] params = {"value1", "value2"};
int rowCount = JPAUtil.executeUpdate(sql, params);

// 删除
String deleteSql = "delete from tableName where field3=?";
Object[] deleteParams = {"deleteValue"};
int deleteRowCount = JPAUtil.executeUpdate(deleteSql, deleteParams);

// 修改
String updateSql = "update tableName set field4=? where field5=?";
Object[] updateParams = {"updateValue", "value5"};
int updateRowCount = JPAUtil.executeUpdate(updateSql, updateParams);

// 查询
String querySql = "select * from tableName where field6=?";
Object[] queryParams = {"queryValue"};
List<Map<String, Object>> results = JPAUtil.executeQuery(querySql, queryParams);
}
}