Calculate volumes based on date - sql

Question

I have this MariaDB table which I would like to use for bar chart:
CREATE TABLE `payment_transaction_daily_facts` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`date` date DEFAULT NULL,
`year` int(11) DEFAULT NULL,
`month` int(11) DEFAULT NULL,
`week` int(11) DEFAULT NULL,
`day` int(11) DEFAULT NULL,
`volume` int(11) DEFAULT NULL,
`count` int(11) DEFAULT NULL,
'created_at' date DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB;
In my example SQL query I have single column for Date. How I can calculate the volumes per day for last 10 days when I have split date, year, month, week and day into different columns?
The final result should be for example:
Date | Amount| Number of transactions per day |
11-11-2018 | 30 | 3 |
11-12-2018 | 230 | 13 |
I tried this:
SELECT SUM(amount) AS sum_volume, COUNT(*) AS sum_Transactions
WHERE (created_at BETWEEN '2018-11-07' AND '2018-11-08')
GROUP BY DATE(created_at)
I want to return the generated data using DTO:
public class DashboardDTO {
private Date date;
private int sum_volume;
private int sum_Transactions;
... getters and setters
}
Rest controller:
#RestController
#RequestMapping("/dashboard")
public class DashboardController {
private static final Logger LOG = LoggerFactory.getLogger(DashboardController.class);
#Autowired
private DashboardRepository dashboardRepository;
#Autowired
private PaymentTransactionsDailyFactsMapper mapper;
#GetMapping("/volumes")
public ResponseEntity<List<DashboardDTO>> getProcessingVolumes(#PathVariable String start_date, #PathVariable String end_date) {
List<DashboardDTO> list = StreamSupport.stream(dashboardRepository.findPaymentTransactionsDailyFacts(start_date, end_date).spliterator(), false)
.map(mapper::toDTO)
.collect(Collectors.toList());
return ResponseEntity.ok(list);
}
}
JPA query:
public List<PaymentTransactionsDailyFacts> findPaymentTransactionsDailyFacts(LocalDateTime start_date, LocalDateTime end_date) {
String hql = "SELECT SUM(amount) AS sum_volume, COUNT(*) AS sum_Transactions " +
" WHERE (created_at BETWEEN :start_date AND :end_date )" +
" GROUP BY DATE(created_at)";
TypedQuery<PaymentTransactionsDailyFacts> query = entityManager.createQuery(hql,
PaymentTransactionsDailyFacts.class).setParameter("start_date", start_date).setParameter("end_date", end_date);
List<PaymentTransactionsDailyFacts> data = query.getResultList();
return data;
}
How should I implement the query properly?
When I receive start_date and end_date as String from Angular how should I convert it into LocaDateTime?

Answer 1

Well, as I commented, time is a dimension in a data warehouse star schema, and I guess period is as well. So you should have two dimension tables, a TimeDim for LocalDate, and a PeriodDim for Period. Then you should have a Fact with the an embeddedId made up of the various dimensions in your schema. Then you would have facts for 1 day periods and facts for 10 day periods. If you insisted on summing facts you have the issue that JPA cannot do a <= or >= comparison against composite keys. Since you are only summing 10 days you could use a in clause to select 10 keys, but again, you should have facts for the periods you need.
#Entity
public class TimeDim {
#Id
private LocalDate localDate;
#Entity
public class PeriodDim {
#Id
private Period period;
// need this too
#Converter(autoApply = true)
public class LocalDateAttributeConverter implements AttributeConverter<LocalDate, Date> {
#Override
public Date convertToDatabaseColumn(LocalDate locDate) {
return (locDate == null ? null : Date.valueOf(locDate));
}
#Override
public LocalDate convertToEntityAttribute(Date sqlDate) {
return (sqlDate == null ? null : sqlDate.toLocalDate());
}
}
#SuppressWarnings("serial")
#Embeddable
public class DimKey implements Serializable {
private LocalDate localDate;
private Period period;
#Entity
public class Fact {
#EmbeddedId
private DimKey dimKey = new DimKey();
private long amount;
And for example:
tx.begin();
TimeDim td10 = new TimeDim();
td10.setLocalDate(LocalDate.now().minusDays(5));
em.persist(td10);
TimeDim td5 = new TimeDim();
td5.setLocalDate(LocalDate.now().minusDays(10));
em.persist(td5);
PeriodDim pd5 = new PeriodDim();
pd5.setPeriod(Period.ofDays(5));
em.persist(pd5);
PeriodDim pd10 = new PeriodDim();
pd10.setPeriod(Period.ofDays(10));
em.persist(pd10);
Fact f10 = new Fact();
f10.getDimKey().setLocalDate(td10.getLocalDate());
f10.getDimKey().setPeriod(pd10.getPeriod());
f10.setAmount(100);
em.persist(f10);
Fact f51 = new Fact();
f51.getDimKey().setLocalDate(td10.getLocalDate());
f51.getDimKey().setPeriod(pd5.getPeriod());
f51.setAmount(50);
em.persist(f51);
Fact f52 = new Fact();
f52.getDimKey().setLocalDate(td5.getLocalDate());
f52.getDimKey().setPeriod(pd5.getPeriod());
f52.setAmount(50);
em.persist(f52);
tx.commit();
em.clear();
DimKey dk = new DimKey();
dk.setLocalDate(td10.getLocalDate());
dk.setPeriod(pd10.getPeriod());
Fact f = em.createQuery("select f from Fact f where f.dimKey = :dimKey", Fact.class)
.setParameter("dimKey", dk)
.getSingleResult();
System.out.println("From 10 day period: " + f.getAmount());
DimKey dk1 = new DimKey();
dk1.setLocalDate(td10.getLocalDate());
dk1.setPeriod(pd5.getPeriod());
DimKey dk2 = new DimKey();
dk2.setLocalDate(td5.getLocalDate());
dk2.setPeriod(pd5.getPeriod());
Long sum = em.createQuery("select sum(f.amount) from Fact f where f.dimKey in (:dimKey1 , :dimKey2)", Long.class)
.setParameter("dimKey1", dk1)
.setParameter("dimKey2", dk2)
.getSingleResult();
System.out.println("From 2*5 day period: " + sum);