Ich habe drei verknüpften Tabellen wie unten:Join zwei, drei verknüpften Tabellen von HQL
+-------------+---------+------------+
| customer_id | name | surname |
+-------------+---------+------------+
| 1 | Jan | Bielecki |
| 2 | Adam | Bielen |
.....
+----------+--------+---------------------+-------------+
| order_id | amount | date | customer_id |
+----------+--------+---------------------+-------------+
| 1 | 10.23 | 2017-02-15 00:00:00 | 1 |
| 2 | 20.56 | 2017-02-16 00:00:00 | 1 |
| 3 | 30.57 | 2017-02-17 00:00:00 | 2 |
| 4 | 40.52 | 2017-02-18 00:00:00 | 2 |
| 5 | 50.30 | 2017-02-19 00:00:00 | 1 |
.....
+-----------------+-----------+------------+----------+
| order_detail_id | item_name | item_price | order_id |
+-----------------+-----------+------------+----------+
| 1 | item 1 | 2.00 | 1 |
| 2 | item 2 | 2.50 | 1 |
| 3 | item 3 | 3.00 | 1 |
| 4 | item 4 | 4.00 | 2 |
| 5 | item 5 | 5.50 | 2 |
| 6 | item 6 | 7.60 | 3 |
| 7 | item 7 | 5.00 | 3 |
| 8 | item 8 | 3.00 | 4 |
| 9 | item 9 | 7.00 | 4 |
| 10 | item 10 | 8.00 | 4 |
| 11 | item 11 | 2.00 | 5 |
| 12 | item 12 | 2.50 | 5 |
.....
Zum einen mit connect ersten und zweiten Tabelle ich kämpfe. Für die Verbindung der Nachnamen mit der Summe des Betrages.
Ich bin wie diese versuchen:
select sum(o.amount) as totalSum
from Order as o,
Customer as c
join c.surname as surname
where c.orders:=o.customer
group by o.customer
order by sum(o.amount) desc
mit diesem Abschnitt zu viele Möglichkeiten zu ändern: where c.orders:=o.customer
Der häufigste Fehler ist Nullpointer.
Vor diesem in SQL getan: Tabelle CUSTOMER_ID < -> TOTAL_AMOUNT
SELECT customer_id,
SUM(amount) as total_amount,
COUNT(amount) as orders_quantity
FROM softhis_db.orders
GROUP BY customer_id;
Tabelle CUSTOMER_ID < -> 3 meisten exp. Aufträge + Termine
SELECT orders.customer_id, orders.amount, orders.date
FROM orders_details
RIGHT JOIN orders
ON orders.order_id = orders_details.order_id
ORDER BY amount DESC
LIMIT 3;
Kunde:
@Entity
@Table(name = "customers")
public class Customer {
@Id
@Column(name = "customer_id")
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
@Column(name = "name", length = 50)
private String name;
@Column(name = "surname", length = 50)
private String surname;
@OneToMany(mappedBy = "customer")
private Set<Order> orders = new HashSet<>();
Auftrag:
@Entity
@Table(name = "orders")
public class Order {
@Id
@Column(name = "order_id")
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
@Column(name = "date")
private Date date;
@Digits(integer = 5, fraction = 2)
@Column(name = "amount")
private BigDecimal amount;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "customer_id")
private Customer customer;
@OneToMany(mappedBy = "order")
private Set<OrderDetail> ordersDetails = new HashSet<>();
Orderdetail:
@Entity
@Table(name = "orders_details")
public class OrderDetail {
@Id
@Column(name = "order_detail_id")
@GeneratedValue(strategy = GenerationType.AUTO)
private Lon id;
@Column(name = "item_name", length = 50)
private String itemName;
@Digits(integer = 5, fraction = 2)
@Column(name = "item_price")
private BigDecimal itemPrice;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "order_id")
private Order order;
Der Punkt ist, wie diese richtig in HQL zu tun? Der nächste Schritt ist die Suche nach Nachnamen und das Ergebnis wie 'Mein Ziel'.
Mein Ziel ist:
+---------+---------------+
| surname | sum of amount |
+---------+---------------+
|Bielecki | 150.40 |
|Bielen | 130.34 |
......
+-----------------------------------+--------------------+
| surname | 3 most expensive orders | date |
+-----------------------------------+--------------------+
|Bielecki | 120.23 |2017-02-15 00:00:00 |
|Bielecki | 80.20 |2017-02-18 00:00:00 |
|Bielecki | 20.20 |2017-02-19 00:00:00 |
+---------+-------------------------+--------------------+
|Bielen | 190.23 |2017-02-15 00:00:00 |
|Bielen | 80.20 |2017-02-18 00:00:00 |
|Bielen | 20.20 |2017-02-19 00:00:00 |
+---------+-------------------------+--------------------+
.....
Bitte erarbeiten Ihr Ziel Ausgabe –
@RaymondNijland was meinst du? – twistezo
zeigt uns die erwartete Ausgabe anhand der Beispieldaten nicht nur Spaltenüberschriften –