存储库
@Repository
public interface ClientRepository extends JpaRepository<ClientEntity, Long> {
@Modifying
@Transactional
@Query(value = "SELECT pp.id, TO_CHAR(pp.created_dt::date, 'dd.mm.yyyy')\n" +
"AS 'Data', CAST(pp.created_dt AS time(0)) AS 'Time', au.username AS 'UserName',\n" +
"ss.name AS 'Service', pp.amount AS 'Amount',\n" +
"REPLACE(pp.status, 'SUCCESS', 'Success') AS 'Payment_status', pp.account AS 'Account',\n" +
"pp.external_id AS 'Idn', COALESCE(pp.external_status, null, 'DN')\n" +
"AS 'Stat'\n" +
"FROM payments AS pp\n" +
"INNER JOIN user AS au ON au.id = pp.creator_id\n" +
"INNER JOIN services AS ss ON ss.id = pp.service_id\n" +
"WHERE pp.created_dt >= '2021-09-28'\n" +
"AND ss.name = 'Faberlic' AND pp.status = 'SUCCESS'", nativeQuery = true)
List<Client> getAllByRegDate();
}
界面
public interface Client {
Long getId();
@JsonFormat(shape = JsonFormat.Shape.STRING)
LocalDate getCreated_dt();
String getUsername();
String getName();
int getAmount();
String getStatus();
String getAccount();
String getExternal_id();
String getExternal_status();
}
DTO
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@ToString
public class ClientDto {
private Long id;
@JsonFormat(shape = JsonFormat.Shape.STRING)
private LocalDate created_dt;
private String username;
private String name;
private int amount;
private String status;
private String account;
private String external_id;
private String external_status;
public ClientDto(Client client) {
this.id = client.getId();
/...
/...
this.external_status = client.getExternal_status();
}
public ClientDto(ClientDto clientDto) {
this.id = clientDto.getId();
/...
this.external_status = clientDto.getExternal_status();
}
public ClientDto(ClientEntity clientEntity) {
}
@Override
public String toString() {
return "" + id + "|" + created_dt + "|" + username + "|" + name +
"|" + amount + "|" + status + "|" + account + "|" + external_id + "|" + external_status;
}
}
实体
@Getter
@NoArgsConstructor
@AllArgsConstructor
@Immutable
@Entity
@Table(name = "payments", schema = "public")
public class ClientEntity {
@Id
private Long id;
@Column(name = "created_dt")
private LocalDate created_dt;
@Column(name = "username")
private String username;
@Column(name = "name")
private String name;
@Column(name = "amount")
private int amount;
@Column(name = "status")
private String status;
@Column(name = "account")
private String account;
@Column(name = "external_id")
private String external_id;
@Column(name = "external_status")
private String external_status;
}
我正在尝试将数据保存到 csv 文件。我从一个数据库、三个表中获取数据。在“名称”中的实体 @Table 中,我指定现有表之一 - “付款”。所有数据都取自三个表(正如我在查询中所写的)。但是当程序运行时,出现错误,“名称”列不存在。该列位于我从中获取数据的另一个表中。不知道我应该做什么。
这更多的是对这个问题和您在here提出的问题的回答。恕我直言,你的结构使事情变得过于复杂,有一个用作投影的
Client
接口,然后将其变成ClientDto
(为什么?投影已经是一个DTO)并且你拥有了你的实体。
JdbcTemplate
和 RowCallbackHandler
将行写入 CSV。这将使用更少的内存,速度更快(因为您不会为每行创建多个对象然后将其丢弃,并且内存中没有所有行)。
import java.io.FileWriter;
import java.sql.ResultSet;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
@Component
public class SchedulerService {
private static final String QUERY = "SELECT pp.id, pp.created_dt au.username, ss.name, pp.amount\n" +
"REPLACE(pp.status, 'SUCCESS', 'Success'), pp.account,\n" +
"pp.external_id AS 'Idn', COALESCE(pp.external_status, null, 'DN') AS 'Stat'\n" +
"FROM payments AS pp\n" +
"INNER JOIN user AS au ON au.id = pp.creator_id\n" +
"INNER JOIN services AS ss ON ss.id = pp.service_id\n" +
"WHERE pp.created_dt >= '2021-09-28'\n" +
"AND ss.name = 'Faberlic' AND pp.status = 'SUCCESS'";
private static final DateTimeFormatter date_format = DateTimeFormatter.ofPattern("dd.MM.yyyy");
private static final DateTimeFormatter time_format = DateTimeFormatter.ofPattern("HH:mm:ss");
private final JdbcTemplate jdbc;
public SchedulerService(JdbcTemplate jdbc) {
this.jdbc = jdbc;
}
@Scheduled(fixedRate = 5000)
public void downloadBlockedClients() {
String filename = "select.csv";
try (FileWriter writer = new FileWriter(filename)) {
writer.append("id|date|time|username|name|amount|status|account|external_id|external_status").append('\n');
this.jdbc.query(QUERY, (ResultSet rs) -> writeLine(writer, rs));
} catch (Exception e) {
e.printStackTrace();
}
}
private void writeLine(FileWriter writer, ResultSet rs) {
try {
LocalDateTime ldt = rs.getTimestamp("created_dt").toLocalDateTime();
writer.append(String.valueOf(rs.getLong("id")));
writer.append('|');
writer.append(ldt.format(date_format));
writer.append('|');
writer.append(ldt.format(time_format));
writer.append('|');
writer.append(rs.getString("username"));
writer.append('|');
writer.append(rs.getString("name"));
writer.append('|');
writer.append(String.valueOf(rs.getBigDecimal("amount")));
writer.append('|');
writer.append(rs.getString("status"));
writer.append('|');
writer.append(rs.getString("account"));
writer.append('|');
writer.append(rs.getString("idn"));
writer.append('|');
writer.append(rs.getString("stat"));
writer.append('\n');
} catch (Exception e) {
throw new IllegalStateException(e);
}
}
}
沿着这些思路的事情将使您的资源更加高效(节省复制,将结果复制到内存中)并且应该更快。您可以将行处理移至一个方法,以便您的 lambda 更具可读性。
注意: 我假设您正在使用 Spring Boot 并且“JdbcTemplate”是开箱即用的。如果没有,您需要在 JPA 配置旁边配置一项。
@Bean
public JdbcTemplate jdbcTemplate(DataSource dataSource) {
return new JdbcTemplate(dataSource);
}
更新 postgres。或者,如果您使用带有标签的 docker-compose 最新设置最后一个稳定版本。