【发布时间】：2018-05-23 18:10:40
【问题描述】：
我想加入 3 个表并得到它们的结果，没有任何重复
SELECT * FROM `database`.project
INNER JOIN post on project.id = post.project_id
INNER JOIN media on media.post_id = post.id
;
电流输出
我想知道输出是否类似于
floaty
Headphone
fasion + technolgie
我尝试使用 distinct 函数。但它只返回我想返回连接表的名称，因为我仍然想使用该数据。
models.py
我正在使用 Project.with_media()
"""models."""
from app import db
from peewee import *
import datetime
class Project(Model):
"""Projects."""
name = CharField(unique=True)
content = CharField()
created_date = DateTimeField(default=datetime.datetime.today())
class Meta(object):
"""Select database."""
database = db
def get_project_media(self):
"""Grab image from get_posts."""
post = Post.select().where(Post.project_id == self).get()
return Media.select().where(Media.post_id == post).get().media
def check_media(self):
"""Check if project has media."""
try:
post = Post.select().where(Post.project_id == self).get()
Media.select().where(Media.post_id == post.id).get()
print('True')
return True
except DoesNotExist:
print('False')
return False
这是我的电话，所以我可以在 jinja 引擎上显示它
def with_media():
"""Grab image from get_posts."""
return (Project.select(Project, Post, Media)
.join(Post)
.join(Media)
.where(Post.id == Media.post_id
and
Project.id == Post.project_id))
def posts(self):
"""Return all posts that are accosicated with this project."""
return Post.select().where(Post.project_id == self)
def media_post(self):
"""Return all posts that are accosicated with this project."""
post = Post.select().where(Post.project_id == self)
return post.get_media()
# return Media.select().where(Media.post_id == post).get()
class Post(Model):
"""Model for posts."""
project = ForeignKeyField(Project, backref='Post', null=True, default=None)
name = CharField()
content = TextField()
"Media Model"
"Category Model"
"Project Model"
created_date = DateTimeField(default=datetime.datetime.today())
class Meta(object):
"""Select database."""
database = db
def get_category(self):
"""Grab all the posts from project."""
return (Category.select()
.where(Category.post_id == self))
def get_media(self):
"""Grab all media from this post."""
return (Media.select()
.where(Media.post_id == self))
def standalone():
"""Return a model of all posts not bound to a project."""
return (Post.select()
.where(Post.project.is_null())
.order_by(Post.created_date.desc()))
def date():
"""Return dates order_by."""
return(Post.select()
.order_by(Post.created_date.desc()))
class Media(Model):
"""Media for post."""
post = ForeignKeyField(Post, backref='Media')
media = CharField()
class Meta(object):
"""Select database."""
database = db
class Category(Model):
"""model for all avaible category's."""
post = ForeignKeyField(Post, backref='Category')
name = CharField()
class Meta(object):
"""Select database."""
database = db
def get_name():
"""Get all category's without overlaping."""
categorys = Category.select()
categoryList = []
for category in categorys:
categoryName = category.name.title()
if categoryName not in categoryList:
categoryList.append(categoryName)
return categoryList
def initialize():
"""Create tables."""
db.connect()
db.create_tables([Category, Project, Post, Media], safe=True)
db.close()
main.py
我想用 media() 函数调用项目，这样我就可以使用数据库项来调用图像和显示内容
<ul class='projects'>
{% for project in projects.with_media() %}
{% if loop.index <= 3 %}
<li class='project_w'>
<img src="{{project.media_post()}}" alt="">
<a href="{{url_for('project', id=project.id)}}">
<h2>{{project.name}}</h2>
</a>
</li>
{% else %}
<li class='project_h'>
<img src="{{project.post.media.media}}" alt="">
<a href="{{url_for('project', id=project.id)}}">
<h2>{{project.name}}</h2>
</a>
</li>
{% endif %}
{% endfor %}
</ul>
【问题讨论】：
-
为什么要开始多行？我假设
project.id是独一无二的，所以在某个地方，每个 ID 都有多行，但根据你的结果，你不应该这样做。发布表架构和表中的相关示例行。请勿发布图片。 -
您需要将预期输出编辑为实际输出。您说自己不想要这些名称。你想要什么做什么？
-
我希望名称与模型 media.media 一起使用，以便在 jinja 中更容易呈现，我编辑了示例以使其更清晰。
标签： python sql flask jinja2 peewee