SQLAlchemy增删改查基本操作,及SQL基本技能样码(join,group)
练了一天,基本的东东应该有感觉了。
#coding=utf-8 from datetime import datetime from sqlalchemy import (MetaData, Table, Column, Integer, Numeric, String, Boolean, DateTime, ForeignKey, ForeignKey, create_engine) from sqlalchemy import (insert, select, update, delete, text, desc, cast, and_, or_, not_) from sqlalchemy.sql import func metadata = MetaData() cookies = Table('cookies', metadata, Column('cookie_id', Integer(), primary_key=True), Column('cookie_name', String(50), index=True), Column('cookie_recipe_url', String(255)), Column('cookie_sku', String(55)), Column('quantity', Integer()), Column('unit_cost', Numeric(12, 2)) ) users = Table('users', metadata, Column('user_id', Integer(), primary_key=True), Column('username', String(15), nullable=False, unique=True), Column('email_address', String(255), nullable=False), Column('phone', String(20), nullable=False), Column('password' ,String(25), nullable=False), Column('created_on', DateTime(), default=datetime.now), Column('updated_on', DateTime(), default=datetime.now, onupdate=datetime.now) ) orders = Table('orders', metadata, Column('order_id', Integer(), primary_key=True), Column('user_id', ForeignKey('users.user_id')), Column('shipped', Boolean(), default=False) ) line_items = Table('line_items', metadata, Column('line_items_id', Integer(), primary_key=True), Column('order_id', ForeignKey('orders.order_id')), Column('cookie_id', ForeignKey('cookies.cookie_id')), Column('quantity', Integer()), Column('extended_cost', Numeric(12, 2)) ) engine = create_engine('mysql+pymysql://user:password@1.2.3.4:3306/cookies') metadata.create_all(engine) connection = engine.connect() ''' s = select([cookies]) rp = connection.execute(s) results = rp.fetchall() print results s = cookies.select() rp = connection.execute(s) # print rp.first() for record in rp: print(record.cookie_name) results = rp.fetchall() first_row = results[0] print first_row[1], first_row.cookie_name, first_row[cookies.c.cookie_name] s = select([cookies.c.cookie_name, cookies.c.quantity]) s = s.order_by(desc(cookies.c.quantity)) s = s.limit(4) rp = connection.execute(s) print(rp.keys()) for cookie in rp: print('{} - {}'.format(cookie.quantity, cookie.cookie_name)) s = select([func.sum(cookies.c.quantity)]) rp = connection.execute(s) print(rp.scalar()) # s = select([func.count(cookies.c.cookie_name)]) s = select([func.count(cookies.c.cookie_name).label('inventory_count')]) rp = connection.execute(s) record = rp.first() print(record.keys()) print(record.inventory_count # s = select([cookies]).where(cookies.c.cookie_name == 'chocolate chip') s = select([cookies]).where(cookies.c.cookie_name.like('%chocolate%')) rp = connection.execute(s) for record in rp.fetchall(): print(record.cookie_name) s = select([cookies.c.cookie_name, 'SKU-' + cookies.c.cookie_sku]) for row in connection.execute(s): print(row) s = select([cookies.c.cookie_name, cast((cookies.c.quantity * cookies.c.unit_cost), Numeric(12, 2)).label('inv_cost')]) for row in connection.execute(s): print('{} - {}'.format(row.cookie_name, row.inv_cost)) s = select([cookies]).where( and_(cookies.c.quantity.between(10, 50), cookies.c.cookie_name.contains('chip') ) ) for row in connection.execute(s): print(row.cookie_name) u = update(cookies).where(cookies.c.cookie_name == "chocolate chip") u = u.values(quantity=(cookies.c.quantity + 120)) result = connection.execute(u) print(result.rowcount) s = select([cookies]).where(cookies.c.cookie_name == "chocolate chip") result = connection.execute(s).first() for key in result.keys(): print('{:>20}: {}'.format(key, result[key])) u = delete(cookies).where(cookies.c.cookie_name == "dark chocolate chip") result = connection.execute(u) print(result.rowcount) s = select([cookies]).where(cookies.c.cookie_name == "dark chocolate chip") result = connection.execute(s).fetchall() print(len(result)) customer_list = [ { 'username': 'cookiemon', 'email_address': 'mon@cookie.com', 'phone': '111-111-1111', 'password': 'password' }, { 'username': 'cakeeater', 'email_address': 'cakeeater@cake.com', 'phone': '222-222-2222', 'password': 'password' }, { 'username': 'pieguy', 'email_address': 'guy@pie.com', 'phone': '333-333-3333', 'password': 'password' } ] ins = users.insert() result = connection.execute(ins, customer_list) ins = insert(orders).values(user_id=1, order_id=1) result = connection.execute(ins) ins = insert(line_items) order_items = [ { 'order_id': 1, 'cookie_id': 1, 'quantity': 2, 'extended_cost': 1.00 }, { 'order_id': 1, 'cookie_id': 3, 'quantity': 12, 'extended_cost': 3.00 } ] result = connection.execute(ins, order_items) ins = insert(orders).values(user_id=2, order_id=2) result = connection.execute(ins) ins = insert(line_items) order_items = [ { 'order_id': 2, 'cookie_id': 1, 'quantity': 24, 'extended_cost': 12.00 }, { 'order_id': 2, 'cookie_id': 4, 'quantity': 6, 'extended_cost': 6.00 } ] result = connection.execute(ins, order_items) columns = [orders.c.order_id, users.c.username, users.c.phone, cookies.c.cookie_name, line_items.c.quantity, line_items.c.extended_cost] cookiemon_orders = select(columns) cookiemon_orders = cookiemon_orders.select_from(orders.join(users).join( line_items).join(cookies)).where(users.c.username == 'cookiemon') result = connection.execute(cookiemon_orders).fetchall() for row in result: print(row) columns = [users.c.username, func.count(orders.c.order_id)] all_orders = select(columns) all_orders = all_orders.select_from(users.outerjoin(orders)) all_orders = all_orders.group_by(users.c.username) result = connection.execute(all_orders).fetchall() for row in result: print(row) def get_orders_by_customer(cust_name, shipped=None, details=False): columns = [orders.c.order_id, users.c.username, users.c.phone] joins = users.join(orders) if details: columns.extend([cookies.c.cookie_name, line_items.c.quantity,line_items.c.extended_cost]) joins = joins.join(line_items).join(cookies) cust_orders = select(columns) cust_orders = cust_orders.select_from(joins) cust_orders = cust_orders.where(users.c.username == cust_name) if shipped is not None: cust_orders = cust_orders.where(orders.c.shipped == shipped) result = connection.execute(cust_orders).fetchall() for row in result: print(row) return result get_orders_by_customer('cakeeater') get_orders_by_customer('cakeeater', details=True) get_orders_by_customer('cakeeater', shipped=True) get_orders_by_customer('cakeeater', shipped=False) get_orders_by_customer('cakeeater', shipped=False, details=True) result = connection.execute("select * from orders").fetchall() print(result) ''' stmt = select([users]).where(text("username='cookiemon'")) print(connection.execute(stmt).fetchall())
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