#encoding: utf-8 from sqlalchemy import create_engine,Column,Integer,String,Float,func,and_,or_ from sqlalchemy.ext.declarative import declarative_base from sqlalchemy.orm import sessionmaker from random import randint HOSTNAME = '127.0.0.1' PORT = 3306 DATABASE = 'first_sqlalchemy' USERNAME = 'root' PASSWORD = '123456' #dialect+driver://username:password@host:port/database DB_URI = "mysql+pymysql://{username}:{password}@{host}:{port}/" \ "{db}?charset=utf8".format(username=USERNAME,password=PASSWORD,host=HOSTNAME,port=PORT,db=DATABASE) engine = create_engine(DB_URI) Base = declarative_base(engine) # Session = sessionmaker(engine) # session = Session() session = sessionmaker(engine)() #Session(**local_kw) 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(String(100)) def __repr__(self): return '<Article(title:%s)>'%self.title # Base.metadata.drop_all() # # Base.metadata.create_all() # # for x in range(6): # article = Article(title='title%s'%x,price=randint(0,100)) # session.add(article) # session.commit() # 1、equal 等於的意思 article = session.query(Article).filter(Article.id == 1).first() article_title = session.query(Article).filter(Article.title == 'title1').first() print(article) print(article_title) # 2、not equal 不等於的意思 article_title_not_equal = session.query(Article).filter(Article.title != 'title0').all() print(article_title_not_equal) #3、like #注意：如果不查詢，直接打印顯示原生sql，不用first（）或 all()方法 article_title_like = session.query(Article).filter(Article.title.like('title%') ).all() #相當於sql select * from article where title like '%title%'; print(article_title_like) #插入一條數據的sql ：insert into article values(null,'abc','100'); # 4、ilike(不區分大小寫) article_title_ilike = session.query(Article).filter(Article.title.ilike('title%') ) print(article_title_ilike) #SELECT article.id AS article_id, article.title AS article_title, article.price AS article_price FROM article # WHERE lower(article.title) LIKE lower(%(title_1)s) # 5、in (在某某里面) #為什么用in_，因為要避開關鍵字in article_title_in = session.query(Article).filter(Article.title.in_(['title1','title2'])).all() print(article_title_in) #原生sql SELECT article.id AS article_id, article.title AS article_title, article.price AS article_price # FROM article # WHERE article.title IN (%(title_1)s, %(title_2)s)%（'title1','title2'），這是格式化字符串，防止sql注入 #6、not in (不在某某里面) article_title_not_in = session.query(Article).filter(Article.title.notin_(['title1','title2'])).all() print(article_title_not_in) #not in (另一種寫法) ~取反的意思 article_title_not_in_1 = session.query(Article).filter(~Article.title.in_(['title1','title2'])).all() print(article_title_not_in_1) # 7、is null 判斷某個字段是否為空 # alter table article add column content text; 添加一列， # 修改原先好的類別 alter table article modify column content varchar(100); # update article set content='python or go' where id =7; 修改一條記錄 is_null_content = session.query(Article).filter(Article.content == None).all() print(is_null_content) # not is null 不為空 not_is_null_content = session.query(Article).filter(Article.content != None) print(not_is_null_content) ''' SELECT article.id AS article_id, article.title AS article_title, article.price AS article_price, article.content AS article_content FROM article WHERE article.content IS NOT NULL ''' #8、and 和 title_and_content = session.query(Article).\ filter(Article.title == 'python or go',Article.content == 'python or go').all() print(title_and_content) #另一種顯示方式 title_and_content_1 = session.query(Article).\ filter(and_(Article.title == 'python or go',Article.content == 'python or go')) print(title_and_content_1) #原生sql顯示SELECT article.id AS article_id, article.title AS article_title, # article.price AS article_price, article.content AS article_content # FROM article # WHERE article.title = %(title_1)s AND article.content = %(content_1)s #9.or title_or_content = session.query(Article).filter\ (or_(Article.title == 'python or go',Article.content == 'python or go')).all() print(title_or_content)