【Flask】filter 常用查询条件

1. equal    2. not equal  3. like, ilike  4.in  5. not in

6. is null  7. is not null  8. and  9. or

#### 如果想查看orm底层查询sql可以在filter函数后面不写人物的函数如：

articles = session.query(Article).filter(Article.title != 'title0')

 # coding:utf-8
 # Author: liangjun.chen

 from datetime import date
 from datetime import datetime
 from datetime import time
 from random import random
 from sqlalchemy import create_engine, Column, Integer, String, Float, Text, and_, or_

 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy.orm import sessionmaker

 HOSTNAME = '127.0.0.1'
 PORT = 3306
 DATABASE = 'sqlalchemy_first'
 USERNAME = 'root'
 PASSWORD = ''

 DB_URI = 'mysql+pymysql://{username}:{password}@{host}:{port}/{dbname}?charset=utf8'.format(
         username=USERNAME, password=PASSWORD, host=HOSTNAME, port=PORT, dbname=DATABASE
 )
 engine = create_engine(DB_URI)
 Base = declarative_base(engine)
 Session = sessionmaker(engine)
 session = Session()

 class Article(Base):
     __tablename__ = 'article'
     id = Column(Integer, primary_key=True, autoincrement=True)
     title = Column(String(50), nullable=False)
     price = Column(Float, nullable=False)
     content = Column(Text)

     def __repr__(self):
         return "Article<title: {}, price: {}>".format(self.title, self.price)

 # 1. equal
 article = session.query(Article).filter(Article.id == 1).first()
 print article

 # 2. not equal
 articles = session.query(Article).filter(Article.title != 'title0').all()
 print articles

 # 3. like, ilike->不区分大小写
 articles = session.query(Article).filter(Article.title.like('title%')).all()
 print articles

 # 4. in
 print '-' * 20
 articles = session.query(Article).filter(Article.title.in_(['title1', 'title2'])).all()
 print articles

 # 5. not in
 print '-' * 20
 articles = session.query(Article).filter(~Article.title.in_(['title2', 'title1'])).all()
 articles2 = session.query(Article).filter(Article.title.notin_(['title2', 'title1'])).all()

 print articles
 print articles2

 # 6. is null
 print '-' * 20
 articles = session.query(Article).filter(Article.content == None).all()
 print articles

 # 7. is not null
 print '-' * 20
 articles = session.query(Article).filter(Article.content != None).all()
 print articles

 # 8. and
 print '-' * 20
 articles = session.query(Article).filter(Article.title == 'title0', Article.content == 'test').all()
 articles_2 = session.query(Article).filter(and_(Article.title == 'title0', Article.content == 'test')).all()
 print articles
 print articles_2

 # 9. or
 print '-' * 20
 articles = session.query(Article).filter(or_(Article.title == 'title1', Article.content == 'test')).all()
 print articles