【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 = '123456'

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