我现在有
学生表(学号、姓名、班号、专业号、系号)
班级表(班号、班名、专业号、系号)
专业表(专业号、专业名、系号)
系表(系号、系名),
然后javabean这样:
public class Student {
private int studentId;
private String studentName;
private int studentClassId;
private int studentSpecialtyId;
private int studentDepartmentId;
private Classes classes;
private Specialty specialty;
private Department department;
}
public class Classes {
private int classId;
private String className;
private int specialtyId;
private int departmentId;
private Specialty specialty;
private Department department;
private ArrayList<Student> students;
}
public class Specialty {
private int specialtyId;
private String specialtyName;
private int specialtyDepartmentId;
private Department department;
private ArrayList<Student> students;
private ArrayList<Classes> classes;
}
public class Department {
我现在有 学生表(学号、姓名、班号、专业号、系号) 班级表(班号、班名、专业号、系号) 专业表(专业号、专业名、系号) 系表(系号、系名), 然后javabean这样: public class Student { private int studentId; private String studentName; private int studentClassId; private int studentSpecialtyId; private int studentDepartmentId
我现在有
学生表(学号、姓名、班号、专业号、系号)
班级表(班号、班名、专业号、系号)
专业表(专业号、专业名、系号)
系表(系号、系名),
然后javabean这样:
public class Student {
private int studentId;
private String studentName;
private int studentClassId;
private int studentSpecialtyId;
private int studentDepartmentId;
private Classes classes;
private Specialty specialty;
private Department department;
}
public class Classes {
private int classId;
private String className;
private int specialtyId;
private int departmentId;
private Specialty specialty;
private Department department;
private ArrayList<Student> students;
}
public class Specialty {
private int specialtyId;
private String specialtyName;
private int specialtyDepartmentId;
private Department department;
private ArrayList<Student> students;
private ArrayList<Classes> classes;
}
public class Department {
private int departmentid;
private String departmentName;
private ArrayList<Student> students;
private ArrayList<Specialty> specialties;
private ArrayList<Classes> classes;
}
然后我怎么用DBUtil查询出学生的信息。也就是说怎么给student里边的classes、specialty、department赋值。
还是我这样的数据库设计有问题。
反正你是用的DBUtil 那只要设计好你的sql语句问题就不好太大
可以用left join 例如:
select T.*,T1.className from student T left join Classes T1 on T1.classId=T.studentClassId
不知是否对你有用
我现在有
学生表(学号、姓名、班号、专业号、系号)
班级表(班号、班名、专业号、系号)
专业表(专业号、专业名、系号)
系表(系号、系名),
然后javabean这样:
public class Student {
private int studentId;
private String studentName;
private int studentClassId;
private int studentSpecialtyId;
private int studentDepartmentId;
private Classes classes;
private Specialty specialty;
private Department department;
}
public class Classes {
private int classId;
private String className;
private int specialtyId;
private int departmentId;
private Specialty specialty;
private Department department;
private ArrayList<Student> students;
}
public class Specialty {
private int specialtyId;
private String specialtyName;
private int specialtyDepartmentId;
private Department department;
private ArrayList<Student> students;
private ArrayList<Classes> classes;
}
public class Department {
private int departmentid;
private String departmentName;
private ArrayList<Student> students;
private ArrayList<Specialty> specialties;
private ArrayList<Classes> classes;
}
然后我怎么用DBUtil查询出学生的信息。也就是说怎么给student里边的classes、specialty、department赋值。
还是我这样的数据库设计有问题。