我有一堂運動和訓練課。我想在每次培訓中進行一組練習。我的問題是——如何在數據庫和 Java 中表示？我想到的是根據表training_id中的外鍵在特定訓練中添加一個練習exercise。但我想將每個練習存儲在一組訓練中，或者只列出訓練課程的一個領域——我認為這是這樣做的好方法，但我可能是錯的。@Entity@Table(name = "exercise")public class Exercise { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name = "exercise_id") private int id; @Column(name = "exercise_name") private String name; @Column(name = "weight") private double weight; @Column(name = "series") private int series; @Column(name = "training_id") private int trainingId;@Table(name = "training")public class Training { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name = "training_id") private int id; @Column(name = "training_name") private String trainingName; @Column(name = "date") private Date date; private Set<Exercise> exercises;也許我不明白它的概念。誰能告訴我正確的方法嗎？
1 回答
慕無忌1623718
TA貢獻1744條經驗 獲得超4個贊
試試這個：
@Table(name = "training")
public class Training {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "training_id")
private int id;
@Column(name = "training_name")
private String trainingName;
@Column(name = "date")
private Date date;
@OneToMany(mappedBy = "training")
private Set<Exercise> exercises = new HashSet<>();
@Entity
@Table(name = "exercise")
public class Exercise {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "exercise_id")
private int id;
@Column(name = "exercise_name")
private String name;
@Column(name = "weight")
private double weight;
@Column(name = "series")
private int series;
@Column(name = "training_id")
private int trainingId;
@ManyToOne
@JsonIgnoreProperties("exercises")
private Training training;
這將是外鍵引用的 2 個單獨的數據庫。
編輯：這將是外鍵引用的2 個單獨的表（不是數據庫）。
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