我在Spring Boot应用程序中有两个实体。一个称为#:kivy 1.11.0
<SelectableButton>:
# Draw a background to indicate selection
canvas.before:
Color:
rgba: (.0, 0.9, .1, .3) if self.selected else (0, 0, 0, 1)
Rectangle:
pos: self.pos
size: self.size
on_press:
app.root.screen_two.populate_fields(self)
<ScreenTwo>:
user_no_text_input: no
user_name_text_input: name
image: image
AccordionItem:
title: "INPUT FIELDS"
GridLayout:
rows:3
BoxLayout:
size_hint: .5, None
height: 600
pos_hint: {'center_x': 1}
padding: 10
spacing: 3
orientation: "vertical"
Label:
text: "Employee ID"
size_hint: (.5, None)
height: 30
TextInput:
id: no
size_hint: (.5, None)
height: 30
multiline: False
Label:
text: "Employee NAME"
size_hint: (.5, None)
height: 30
TextInput:
id: name
size_hint: (.5, None)
height: 30
multiline: False
Label:
text: "Employee PHOTO"
size_hint: (.5, None)
height: 30
Image:
id: image
allow_stretch: True
keep_ratio: True
Button:
text: "SELECT IMAGE"
size_hint_y: None
height: self.parent.height * 0.2
on_release: root.filechooser()
Button:
id: save_btn
text: "SAVE BUTTON"
height: 50
on_press: root.save()
AccordionItem:
title: "RECYCLE VIEW"
BoxLayout:
orientation: "vertical"
GridLayout:
size_hint: 1, None
size_hint_y: None
height: 25
cols: 2
Label:
text: "Employee ID"
Label:
text: "Employee Name"
# Display only the first two columns Employee ID and Employee Name NOT EmployeePhoto on the RecycleView
BoxLayout:
RecycleView:
viewclass: 'SelectableButton'
data: root.data_items
SelectableRecycleGridLayout:
cols: 2
default_size: None, dp(26)
default_size_hint: 1, None
size_hint_y: None
height: self.minimum_height
orientation: 'vertical'
multiselect: True
touch_multiselect: True
Button:
text: "On Screen 2 >> Go to Screen 1"
on_press: root.manager.current = 'screen1'
，其中包含有关一段时间的乐器的元数据。另一个称为visit，它反映了在访问期间该仪器是如何连接的。
在数据库中，visit.attachment_id是附件的可为空的外键。多次访问可以引用相同的附件记录，但是一次访问根本不需要引用附件。数据库中存在任何访问未引用的孤立孤岛附件记录。
attachment//Imports...
@Entity
@Data
@SequenceGenerator(name = "visit_seq_gen", sequenceName = "visit_seq", allocationSize = 1)
@Table(name = "VISIT")
public class Visit implements Serializable {
@Id
@GeneratedValue( strategy = GenerationType.SEQUENCE, generator = "visit_seq_gen" )
@Column(name = "VISIT_ID")
private Long visitId;
//Other fields...
@ManyToOne( fetch=FetchType.LAZY, cascade=CascadeType.ALL )
@JoinColumn(name = "ATTACHMENT_ID")
private Attachment attachment;
}
每次我更新现有的访问记录时，都会创建一个新的附件记录。尽管有//Imports...
@Entity
@Data
@SequenceGenerator(name = "attachment_seq_gen", sequenceName = "attachment_seq", allocationSize = 1)
@Table(name = "ATTACHMENT")
public class Attachment implements Serializable {
@Id
@GeneratedValue( strategy = GenerationType.SEQUENCE, generator = "attachment_seq_gen" )
@Column(name = "ATTACHMENT_ID")
private Long attachmentId;
//Other fields...
@JsonIgnore
@OneToMany(mappedBy="attachment", orphanRemoval=true)
private Set<Visit> visitSet;
}
，仍未删除旧的附件记录。有什么想法吗？