def test_sub_transaction_outer_rollback(account_table):
"""
测试 这么一个过程, A 收到由 B 转过来的钱, 然后, A 还钱给 W.
一开始他们都是 500 块钱.
"""
from bank.app import engine, Account
conn = engine.connect()
Account._conn = conn
ac_a = Account.find_by_name('A')
ac_b = Account.find_by_name('B')
ac_w = Account.find_by_name('W')
assert ac_a.amount == 500
assert ac_b.amount == 500
assert ac_w.amount == 500
def a_pay_money_to_w():
with conn.begin_nested():
ac_a.amount -= 100
ac_a.save()
ac_w.amount += 100
ac_w.save()
def a_receive_salary_from_b():
with conn.begin():
ac_a.amount += 100
ac_a.save()
ac_b.amount -= 100
ac_b.save()
a_pay_money_to_w()
raise Exception("Bad Exception")
try:
a_receive_salary_from_b()
except Exception as e:
print(e)
ac_a2 = Account.find_by_name('A')
ac_b2 = Account.find_by_name('B')
ac_w2 = Account.find_by_name('W')
assert ac_a2.amount == 500
assert ac_b2.amount == 500
assert ac_w2.amount == 500
def test_nested_transaction(account_table):
"""
测试 这么一个过程, A 收到由 B 转过来的钱, 然后, A 还钱给 W.
一开始他们都是 500 块钱.
"""
from bank.app import engine, Account
conn = engine.connect()
Account._conn = conn
ac_a = Account.find_by_name('A')
ac_b = Account.find_by_name('B')
ac_w = Account.find_by_name('W')
assert ac_a.amount == 500
assert ac_b.amount == 500
assert ac_w.amount == 500
def a_pay_money_to_w():
with conn.begin():
ac_a.amount -= 100
ac_a.save()
ac_w.amount += 100
ac_w.save()
def a_receive_salary_from_b():
with conn.begin():
ac_a.amount += 100
ac_a.save()
ac_b.amount -= 100
ac_b.save()
a_pay_money_to_w()
a_receive_salary_from_b()
ac_a2 = Account.find_by_name('A')
ac_b2 = Account.find_by_name('B')
ac_w2 = Account.find_by_name('W')
assert ac_a2.amount == 500
assert ac_b2.amount == 400
assert ac_w2.amount == 600
def account_table():
from bank.app import engine, metadata, account_table as accounts
# 1) 重新创建表
metadata.drop_all(engine)
metadata.create_all(engine)
# 2) 初始化表数据
conn = engine.connect()
conn.execute(accounts.insert(), [
{
'name': 'A',
'amount': 500
},
{
'name': 'B',
'amount': 500
},
{
'name': 'W',
'amount': 500
},
])
return accounts