flask ORM: Flask-SQLAlchemy【多表多对多】增删改查

案例表：

 1 # coding=utf-8
 2 from flask_sqlalchemy import SQLAlchemy
 3 
 4 db = SQLAlchemy()
 5 
 6 
 7 tags_class = db.Table('tags_classifications',
 8     db.Column('tag_id', db.Integer, db.ForeignKey('tag.id')),
 9     db.Column('classify_id', db.Integer, db.ForeignKey('classification.id'))
10 )
11 
12 class Classification(db.Model):
13     __tablename__ = 'classification'
14     id = db.Column(db.Integer, primary_key=True)
15     title = db.Column(db.String(1024), unique=True)
16     img_title = db.Column(db.String(1024))
17     img_url = db.Column(db.String(2048))
18 
19     tags = db.relationship('Tag', secondary=tags_class,
20                            backref=db.backref('classifications', lazy='dynamic'))
21 
22 
23     def __init__(self, title,img_title,img_url):
24         self.title = title
25         self.img_title = img_title
26         self.img_url = img_url
27 
28     def __repr__(self):
29         return '' % self.title
30 
31 class Tag(db.Model):
32     __tablename__ = 'tag'
33     id = db.Column(db.Integer, primary_key=True)
34     name = db.Column(db.String(1024), unique=True)
35     img_title = db.Column(db.String(1024))
36     img_url = db.Column(db.String(2048))
37 
38 
39     def __init__(self, name,img_title,img_url):
40         self.name = name
41         self.img_title = img_title
42         self.img_url = img_url
43 
44     def __repr__(self):
45         return '' % self.name

models.py

flask 路由表插入数据：

 1 # coding=utf-8
 2 import os
 3 import random
 4 from flask import Blueprint, request, session
 5 from flask import render_template, redirect, jsonify
 6 from shengyuanapp.models import db, Classification,Tag
 7 bp = Blueprint(__name__, 'home')
 8 
 9 
10 base_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
11 img_path = os.path.join(base_dir,"static","img","bmp")
12 img_full_path = []
13 classify_obj_list = []
14 tags_obj_list = []
15 
16 
17 list_img = os.listdir(img_path)
18 for i in list_img:
19     tmp_dir = os.path.join(img_path,i)
20     img_full_path.append(tmp_dir)
21 
22 
23 def gen_tags():
24     """
25     
26     :return: 
27     """
28     tags_list = []
29     for i in img_full_path:
30         tag_name = "tag_" + str(img_full_path.index(i))
31         img_title = "img_%s" % (img_full_path.index(i))
32         img_url = i
33         tag = Tag(name=tag_name,img_title=img_title,img_url=img_url)
34         tags_list.append(tag)
35     return tags_list
36 
37 def gen_classifications():
38     """
39     
40     :return: 
41     """
42     pages_list = []
43     tags = gen_tags()
44     for i in img_full_path:
45         title = "calssification" + str(img_full_path.index(i))
46         img_title = "img_%s" % (img_full_path.index(i))
47         img_url = i
48         page_obj = Classification(title=title,img_title=img_title,img_url=img_url)
49         page_obj.tags = tags
50         pages_list.append(page_obj)
51 
52     return pages_list
53 
54 
55 @bp.route('/', methods=('GET', 'POST'))
56 def home():
57 
58     return render_template('index.html')
59 
60 @bp.route('/insert_img',methods=('GET', 'POST'))
61 def insert_img():
62 
63     classes = gen_classifications()  # 生成的 gen_classification 对象列表。
64     db.session.add_all(classes)  # 一次性添加所有 gen_classification。
65     db.session.commit()  # 提交到数据库

routes

flask 路由表查询：

 1 @bp.route('/query_img', methods=('GET', 'POST'))
 2 def query_img():
 3     obj_id = random.choice(list(range(10)))
 4     tag_name = "tag_" + str(obj_id)
 5     tag = Tag.query.filter_by(name=tag_name).first()
 6     print("tag: ", tag)
 7 
 8     classi_title = "calssification" + str(obj_id)
 9     classi = Classification.query.filter_by(title=classi_title).first()
10     print("classi", classi.tags)

routes

 

转载于:https://www.cnblogs.com/adamans/articles/8988147.html