标签：查询 too 反向 lse cte type edit pos lang
url(r‘^student_list/‘, app01_views.student_list, name="student_list"),
def student_list(request): student_list = models.Student.objects.all() return render(request, "student_list.html", {"student_list": student_list})
<!DOCTYPE html> <html lang="zh-CN"> <head> <meta charset="UTF-8"> <meta http-equiv="x-ua-compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>学生列表</title> </head> <body> <a href="{% url ‘add_student‘ %}">添加学生</a> <table border="1"> <thead> <tr> <th>#</th> <th>id</th> <th>学生姓名</th> <th>学生班级</th> <th>开班日期</th> <th>操作</th> </tr> </thead> <tbody> {% for student in student_list%} <tr> <td>{{ forloop.counter}}</td> <td>{{ student.id }}</td> <td>{{ student.sname }}</td> <td>{{ student.cid.cname }}</td> <td>{{ student.cid.first_day|date:‘Y-m-d‘ }}</td> <td> <a href="{% url ‘delete_student‘ student.id %}">删除</a> <a href="{% url ‘edit_student‘ student.id %}">编辑</a> </td> </tr> {% endfor %} </tbody> </table> </body> </html>
url(r‘^delete_student/(?P<sid>\d+)$‘, app01_views.delete_student, name="delete_student"),
def delete_student(request, sid): models.Student.objects.filter(id=sid).delete() return redirect(reverse("student_list"))
<a href="{% url ‘delete_student‘ student.id %}">删除</a>
url(r‘^add_student/$‘, app01_views.add_student, name="add_student"),
def add_student(request): if request.method == "POST": sname = request.POST.get("sname") class_id = request.POST.get("class_id") models.Student.objects.create(sname=sname, cid_id=class_id) return redirect(reverse("student_list")) class_list = models.Class.objects.all() return render(request, "add_student.html", {"class_list": class_list})
<!DOCTYPE html> <html lang="zh-CN"> <head> <meta charset="UTF-8"> <meta http-equiv="x-ua-compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>添加学生</title> </head> <body> <form action="{% url ‘add_student‘ %}" method="post"> {% csrf_token %} <p>学生姓名：<input type="text" name="sname"></p> <label for="class_id">所在班级：</label> <select name="class_id" id="class_id"> {% for class in class_list %} <option value="{{ class.id }}">{{ class.cname }}</option> {% endfor %} </select> <p><input type="submit" value="提交"></p> </form> </body> </html>
url(r‘^edit_student/(?P<sid>\d+)$‘, app01_views.edit_student, name="edit_student"),
def edit_student(request, sid): # 获取到编辑的学生对象 student_obj = models.Student.objects.get(id=sid) # 获取所有的班级数据 class_list = models.Class.objects.all() if request.method == "POST": sname = request.POST.get("sname") class_id = request.POST.get("class_id") student_obj.sname = sname student_obj.cid_id = class_id student_obj.save() return redirect(reverse("student_list")) return render(request, "edit_student.html", {"student": student_obj, "class_list": class_list})
<!DOCTYPE html> <html lang="zh-CN"> <head> <meta charset="UTF-8"> <meta http-equiv="x-ua-compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>编辑学生信息</title> </head> <body> <form action="{% url ‘edit_student‘ student.id %}" method="post"> {% csrf_token %} <p>学生姓名：<input type="text" name="sname" value="{{ student.sname }}"></p> <label for="class_id">所在班级：</label> <select name="class_id" id="class_id"> {% for class in class_list %} {% if class.id == student.cid_id %} <option value="{{ class.id }}" selected>{{ class.cname }}</option> {% else %} <option value="{{ class.id }}">{{ class.cname }}</option> {% endif %} {% endfor %} </select> <p><input type="submit" value="提交"></p> </form> </body> </html>
正向查询（由学生表查询班级表）
查询学生的班级信息
>>> student_obj = models.Student.objects.first() >>> student_obj.cid # 通过model类中的属性查找到对应的外键数据对象 <Class: Class object> >>> student_obj.cid.cname ‘1班‘ >>> student_obj.cid_id # 获取实际外键的值 1
反向查询（由班级表查询学生表）
查询班级的学生信息
>>> class_obj = models.Class.objects.first() # 获取第一个班级对象 >>> class_obj.student_set.all() # 通过表名_set反向查询出所有的学生 <QuerySet [<Student: Student object>, <Student: Student object>]>
注意：
如果不在外键的字段中设置related_name的话，默认就用表名_set。
如果设置了related_name="students"，反向查询时可直接使用students进行反向查询。
>>> class_obj.students.all()
表结构设计
class Student(models.Model): sname = models.CharField(max_length=32, verbose_name="学生姓名") the_class = models.ForeignKey(to=Class, to_field="id", on_delete=models.CASCADE, related_name="students") detail = models.OneToOneField(to="StudentDetail", null=True) class StudentDetail(models.Model): height = models.PositiveIntegerField() weight = models.PositiveIntegerField() email = models.EmailField()
正向查询（由学生信息表查询学生详情表）
>>> student_obj = models.Student.objects.first() >>> student_obj.detail.email ‘1@1.com‘
反向查询（由学生详情表反向查询学生信息表）
>>> detail_obj = models.StudentDetail.objects.get(id=1) >>> detail_obj.student.sname ‘a‘
标签：查询 too 反向 lse cte type edit pos lang
原文地址：https://www.cnblogs.com/zyling/p/12812920.html
