Задание 1:
```
from sqlalchemy import create_engine
import os
eng = create_engine("sqlite:///some.db")
e.execute("""create table employee (emp_id integer primary key,emp_name varchar)""")
e.execute("insert into employee (emp_id, emp_name) values (1,'dilbert')
r = eng.execute("select * from employee")
print(r)
```
Задание 2:
```
from sqlalchemy import String, Integer, DateTime, ForeignKey
from sqlalchemy import inspect
eng = create_engine("sqlite:///some.db")
metadata = MetaData()
net_table = Table('network', metadata,
                    Column('network_id', Integer, primary_key=True),
                    Column('name', String, nullable=False),
                    Column('created_at', DateTime, nullable=False),
                    Column('owner_id', Integer, ForeignKey('user.id'))
                    )
user_table = Table('user', metaData,
                   Column('id', Integer, primary_key=True),
                   Column('name', String),
                   Column('fullname', String)
                   )
metadata.create_all(eng)
metadata2 = MetaData()
reflected = Table('user', metadata2, autoload=True, autoload_with=eng)
inspector = inspect(eng)
inspector.get_columns('network')

for inspect_table in inspector.get_table_names():
    for inspect_column in inspector.get_columns(inspect_table):
        if inspect_column ['name'] == 'story_id':
            print (inspect_table)
```
Задание 3:
```
from sqlalchemy import String, Integer, DateTime, ForeignKey
from sqlalchemy import inspect
from sqlalchemy import select
from sqlalchemy import create_engine
from sqlalchemy.orm import aliased
eng= create_engine("sqlite:///some.db")
metaData = MetaData()
user_table = Table('user', metaData,
                    Column('id', Integer, primary_key=True),
                    Column('username', String(50)),
                    Column('fullname', String(50))
                   )
metaData1.create_all(eng)
print(user_table.c.username == 'ed')
print(and_(user_table.c.fullname == 'ed',user_table.c.id > 5))
print(or_(user_table.c.username == 'ed',and_(user_table.c.fullname == 'ed',user_table.c.id > 5)))
add = user_table.insert().values(username='dilbert', fullname='Dilbert Jones')
connection = engine.connect()
r = connection.execute(add)
print(r)

sel = select([user_table.c.username, user_table.c.fullname]).\
    where(
        or_(user_table.c.username == 'wendy',user_table.c.username == 'dilbert')
    ).\
    order_by(user_table.c.fullname)
print(connection.execute(sel)
addr_table = Table("address", metadata,
                        Column('id', Integer, primary_key=True),
                        Column('user_id', Integer, ForeignKey('user.id'), nullable=False),
                        Column('email_address', String(100), nullable=False)
                      )
metadata.create_all(engine)
conn.execute(addr_table.insert(), [
    {"user_id": 1, "email_address": "ed@ed.com"},
    {"user_id": 1, "email_address": "ed@gmail.com"},
    {"user_id": 2, "email_address": "jack@yahoo.com"},
    {"user_id": 3, "email_address": "wendy@gmail.com"},
])
text = select([user_table.c.fullname, addr_table.c.email_address]).\
    select_from(user_table.join(addr_table)).\
    where(user_table.c.username=='ed').\
    order_by(addr_table.c.email_address)
print(text)
result = user_table.update().values(fullname="Ed Jones").where(user_table.c.username == 'ed')
print(result)
```
Задание 4:
```
from sqlalchemy import Column, Integer, String, Numeric, func,ForeignKey
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import Session,relationship
from sqlalchemy import create_engine

mybase = declarative_base()
eng = create_engine("sqlite:///some.db")
connection=eng.connect()
class Network(mybase):
    __tablename__ = 'network'
    network_id = Column(Integer, primary_key=True)
    name = Column(String(100), nullable = False)
    def __repr__(self):
        return "<Network(%r, %r)>" % (self.name)
class User(mybase):
    __tablename__ = 'user'
    id = Column(Integer, primary_key=True)
    name = Column(String)
    fullname = Column(String)
    def __repr__(self):
        return "<User(%r, %r)>" % (self.name, self.fullname)
class Address(mybase):
    __tablename__ = 'address'
    id = Column(Integer, primary_key=True)
    email_address = Column(String, nullable=False)
    user_id = Column(Integer, ForeignKey('user.id'))
    user = relationship("User", backref="addresses")
    def __repr__(self):
        return "<Address(%r)>" % self.email_address
class Account(mybase):
    __tablename__ = 'account'
    id = Column(Integer, primary_key=True)
    owner = Column(String(50), nullable = False)
    balance = Column(Numeric, default=0)
    def __repr__(self):
        return "<Account(%r, %r)>" % (self.owner, self.balance)
class Transaction(myBase):
    __tablename__ = 'transaction'
    id = Column(Integer, primary_key=True)
    amount = Column(Numeric, nullable=False)
    account_id = Column(Integer, ForeignKey(Account.__tablename__ + '.id'), nullable=False)
    account = relationship('Account', backref="transactions")
    def __repr__(self):
        return "Transaction: %r" % (self.amount)
mybase.metadata.create_all(eng)
session = Session(bind=eng)
session.add(Network(name = 'net1'))
session.add(Network(name = 'net2'))
session.commit()
print(eng.execute("select * from network")
session1 = Session(bind=eng)
session1.add_all([
    User(name='wendy', fullname='Wendy Weathersmith'),
    User(name='mary', fullname='Mary Contrary'),
    User(name='fred', fullname='Fred Flinstone')
])
session1.commit()
q1 = session1.query(User).order_by(User.fullname)
print(q1)
q2 = q1.filter(User.name.in_(['mary','ed']))
print(q2)
session2=Session(bind = eng)
acc1=Account(owner = "Jack Jones", balance = 5000)
acc2=Account(owner="Ed Rendell", balance=10000)
session3.add_all([
    acc1,
    acc2,
    Transaction(amount=500, account=acc1),
    Transaction(amount=4500, account=acc1),
    Transaction(amount=6000, account=acc2),
    Transaction(amount=4000, account=acc2)])
for account in session2.query(Account).all():
    print(account.owner)
    print(account.balance)
    m = 0
    for at in account.transactions:
        m += at.amount
print(m)
```