private and course

buisnesslogic/src/main/java/com/plannaplan/entities/Course.java

@@ -0,0 +1,41 @@
+package com.plannaplan.entities;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.OneToMany;
+
+@Entity
+public class Course {
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private Long id;
+    private String name;
+    private String symbol;
+    @OneToMany(mappedBy = "id")
+    private List<Groups> groups = new ArrayList<>();
+
+    public Course() {
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public String getSymbol() {
+        return symbol;
+    }
+
+    public void setSymbol(String symbol) {
+        this.symbol = symbol;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+}

buisnesslogic/src/main/java/com/plannaplan/entities/Groups.java

@@ -15,7 +15,9 @@ public class Groups {
     @Id
     @GeneratedValue(strategy = GenerationType.AUTO)
     private Long id;
-    private Long courseId;
+    @ManyToOne
+    @JoinColumn(name = "course_id")
+    private Course courseId;
     private int time;
     private String room;
     private int capacity;
@@ -76,11 +78,11 @@ public class Groups {
         this.time = time;
     }
 
-    public Long getCourseId() {
+    public Course getCourseId() {
         return courseId;
     }
 
-    public void setCourseId(Long courseId) {
+    public void setCourseId(Course courseId) {
         this.courseId = courseId;
     }
 }