All db operations now should go thru Database object

This commit is contained in:
Václav 'Ax' Hůla 2012-10-27 23:20:43 +02:00
parent ffa119e7f0
commit a4dbf3b77c
5 changed files with 128 additions and 100 deletions

View file

@ -5,6 +5,8 @@ import psycopg2
from PySide import QtCore, QtGui, QtDeclarative
from brmbar import Database
import brmbar
@ -173,7 +175,7 @@ class ShopAdapter(QtCore.QObject):
db.commit()
return balance
db = psycopg2.connect("dbname=brmbar")
db = Database.Database("dbname=brmbar")
shop = brmbar.Shop.new_with_defaults(db)
currency = shop.currency
db.commit()

View file

@ -17,31 +17,25 @@ class Account:
@classmethod
def load_by_barcode(cls, db, barcode):
with closing(db.cursor()) as cur:
cur.execute("SELECT account FROM barcodes WHERE barcode = %s", [barcode])
res = cur.fetchone()
if res is None:
return None
id = res[0]
res = db.execute_and_fetch("SELECT account FROM barcodes WHERE barcode = %s", [barcode])
if res is None:
return None
id = res[0]
return cls.load(db, id = id)
@classmethod
def load(cls, db, id = None, name = None):
""" Constructor for existing account """
if id is not None:
with closing(db.cursor()) as cur:
cur.execute("SELECT name FROM accounts WHERE id = %s", [id])
name = cur.fetchone()[0]
name = db.execute_and_fetch("SELECT name FROM accounts WHERE id = %s", [id])
name = name[0]
elif name is not None:
with closing(db.cursor()) as cur:
cur.execute("SELECT id FROM accounts WHERE name = %s", [name])
id = cur.fetchone()[0]
id = db.execute_and_fetch("SELECT id FROM accounts WHERE name = %s", [name])
id = id[0]
else:
raise NameError("Account.load(): Specify either id or name")
with closing(db.cursor()) as cur:
cur.execute("SELECT currency, acctype FROM accounts WHERE id = %s", [id])
currid, acctype = cur.fetchone()
currid, acctype = db.execute_and_fetch("SELECT currency, acctype FROM accounts WHERE id = %s", [id])
currency = Currency.load(db, id = currid)
return cls(db, name = name, id = id, currency = currency, acctype = acctype)
@ -49,17 +43,15 @@ class Account:
@classmethod
def create(cls, db, name, currency, acctype):
""" Constructor for new account """
with closing(db.cursor()) as cur:
cur.execute("INSERT INTO accounts (name, currency, acctype) VALUES (%s, %s, %s) RETURNING id", [name, currency.id, acctype])
id = cur.fetchone()[0]
id = db.execute_and_fetch("INSERT INTO accounts (name, currency, acctype) VALUES (%s, %s, %s) RETURNING id", [name, currency.id, acctype])
id = id[0]
return cls(db, name = name, id = id, currency = currency, acctype = acctype)
def balance(self):
with closing(self.db.cursor()) as cur:
cur.execute("SELECT SUM(amount) FROM transaction_splits WHERE account = %s AND side = %s", [self.id, 'debit'])
debit = cur.fetchone()[0] or 0
cur.execute("SELECT SUM(amount) FROM transaction_splits WHERE account = %s AND side = %s", [self.id, 'credit'])
credit = cur.fetchone()[0] or 0
debit = self.db.execute_and_fetch("SELECT SUM(amount) FROM transaction_splits WHERE account = %s AND side = %s", [self.id, 'debit'])
debit = debit[0] or 0
credit = self.db.execute_and_fetch("SELECT SUM(amount) FROM transaction_splits WHERE account = %s AND side = %s", [self.id, 'credit'])
credit = credit[0] or 0
return debit - credit
def balance_str(self):
@ -76,15 +68,12 @@ class Account:
def _transaction_split(self, transaction, side, amount, memo):
""" Common part of credit() and debit(). """
with closing(self.db.cursor()) as cur:
cur.execute("INSERT INTO transaction_splits (transaction, side, account, amount, memo) VALUES (%s, %s, %s, %s, %s)", [transaction, side, self.id, amount, memo])
self.db.execute("INSERT INTO transaction_splits (transaction, side, account, amount, memo) VALUES (%s, %s, %s, %s, %s)", [transaction, side, self.id, amount, memo])
def add_barcode(self, barcode):
with closing(self.db.cursor()) as cur:
cur.execute("INSERT INTO barcodes (account, barcode) VALUES (%s, %s)", [self.id, barcode])
self.db.execute("INSERT INTO barcodes (account, barcode) VALUES (%s, %s)", [self.id, barcode])
self.db.commit()
def rename(self, name):
with closing(self.db.cursor()) as cur:
cur.execute("UPDATE accounts SET name = %s WHERE id = %s", [name, self.id])
self.db.execute("UPDATE accounts SET name = %s WHERE id = %s", [name, self.id])
self.name = name

View file

@ -20,13 +20,11 @@ class Currency:
def load(cls, db, id = None, name = None):
""" Constructor for existing currency """
if id is not None:
with closing(db.cursor()) as cur:
cur.execute("SELECT name FROM currencies WHERE id = %s", [id])
name = cur.fetchone()[0]
name = db.execute_and_fetch("SELECT name FROM currencies WHERE id = %s", [id])
name = name[0]
elif name is not None:
with closing(db.cursor()) as cur:
cur.execute("SELECT id FROM currencies WHERE name = %s", [name])
id = cur.fetchone()[0]
id = db.execute_and_fetch("SELECT id FROM currencies WHERE name = %s", [name])
id = id[0]
else:
raise NameError("Currency.load(): Specify either id or name")
return cls(db, name = name, id = id)
@ -34,52 +32,44 @@ class Currency:
@classmethod
def create(cls, db, name):
""" Constructor for new currency """
with closing(db.cursor()) as cur:
cur.execute("INSERT INTO currencies (name) VALUES (%s) RETURNING id", [name])
id = cur.fetchone()[0]
id = db.execute_and_fetch("INSERT INTO currencies (name) VALUES (%s) RETURNING id", [name])
id = id[0]
return cls(db, name = name, id = id)
def rates(self, other):
""" Return tuple ($buy, $sell) of rates of $self in relation to $other (brmbar.Currency):
$buy is the price of $self in means of $other when buying it (into brmbar)
$sell is the price of $self in means of $other when selling it (from brmbar) """
with closing(self.db.cursor()) as cur:
cur.execute("SELECT rate, rate_dir FROM exchange_rates WHERE target = %s AND source = %s AND valid_since <= NOW() ORDER BY valid_since DESC LIMIT 1", [self.id, other.id])
res = cur.fetchone()
if res is None:
raise NameError("Currency.rate(): Unknown conversion " + other.name() + " to " + self.name())
buy_rate, buy_rate_dir = res
buy = buy_rate if buy_rate_dir == "target_to_source" else 1/buy_rate
res = self.db.execute_and_fetch("SELECT rate, rate_dir FROM exchange_rates WHERE target = %s AND source = %s AND valid_since <= NOW() ORDER BY valid_since DESC LIMIT 1", [self.id, other.id])
if res is None:
raise NameError("Currency.rate(): Unknown conversion " + other.name() + " to " + self.name())
buy_rate, buy_rate_dir = res
buy = buy_rate if buy_rate_dir == "target_to_source" else 1/buy_rate
cur.execute("SELECT rate, rate_dir FROM exchange_rates WHERE target = %s AND source = %s AND valid_since <= NOW() ORDER BY valid_since DESC LIMIT 1", [other.id, self.id])
res = cur.fetchone()
if res is None:
raise NameError("Currency.rate(): Unknown conversion " + self.name() + " to " + other.name())
sell_rate, sell_rate_dir = res
sell = sell_rate if sell_rate_dir == "source_to_target" else 1/sell_rate
res = self.db.execute_and_fetch("SELECT rate, rate_dir FROM exchange_rates WHERE target = %s AND source = %s AND valid_since <= NOW() ORDER BY valid_since DESC LIMIT 1", [other.id, self.id])
if res is None:
raise NameError("Currency.rate(): Unknown conversion " + self.name() + " to " + other.name())
sell_rate, sell_rate_dir = res
sell = sell_rate if sell_rate_dir == "source_to_target" else 1/sell_rate
return (buy, sell)
return (buy, sell)
def convert(self, amount, target):
with closing(self.db.cursor()) as cur:
cur.execute("SELECT rate, rate_dir FROM exchange_rates WHERE target = %s AND source = %s AND valid_since <= NOW() ORDER BY valid_since DESC LIMIT 1", [target.id, self.id])
res = cur.fetchone()
if res is None:
raise NameError("Currency.convert(): Unknown conversion " + self.name() + " to " + other.name())
rate, rate_dir = res
if rate_dir == "source_to_target":
resamount = amount * rate
else:
resamount = amount / rate
return resamount
res = self.db.execute_and_fetch("SELECT rate, rate_dir FROM exchange_rates WHERE target = %s AND source = %s AND valid_since <= NOW() ORDER BY valid_since DESC LIMIT 1", [target.id, self.id])
if res is None:
raise NameError("Currency.convert(): Unknown conversion " + self.name() + " to " + target.name())
rate, rate_dir = res
if rate_dir == "source_to_target":
resamount = amount * rate
else:
resamount = amount / rate
return resamount
def str(self, amount):
return "{:.2f} {}".format(amount, self.name)
def update_sell_rate(self, target, rate):
with closing(self.db.cursor()) as cur:
cur.execute("INSERT INTO exchange_rates (source, target, rate, rate_dir) VALUES (%s, %s, %s, %s)", [self.id, target.id, rate, "source_to_target"])
self.db.execute("INSERT INTO exchange_rates (source, target, rate, rate_dir) VALUES (%s, %s, %s, %s)", [self.id, target.id, rate, "source_to_target"])
def update_buy_rate(self, source, rate):
with closing(self.db.cursor()) as cur:
cur.execute("INSERT INTO exchange_rates (source, target, rate, rate_dir) VALUES (%s, %s, %s, %s)", [source.id, self.id, rate, "target_to_source"])
self.db.execute("INSERT INTO exchange_rates (source, target, rate, rate_dir) VALUES (%s, %s, %s, %s)", [source.id, self.id, rate, "target_to_source"])

View file

@ -0,0 +1,50 @@
"""self-reconnecting database object"""
import psycopg2
from contextlib import closing
import time
class Database:
"""self-reconnecting database object"""
def __init__(self, dsn):
self.db_conn = psycopg2.connect(dsn)
self.dsn = dsn
def execute(self, query, attrs = None):
"""execute a query and return one result"""
with closing(self.db_conn.cursor()) as cur:
cur = self._execute(cur, query, attrs)
def execute_and_fetch(self, query, attrs = None):
"""execute a query and return one result"""
with closing(self.db_conn.cursor()) as cur:
cur = self._execute(cur, query, attrs)
return cur.fetchone()
def execute_and_fetchall(self, query, attrs = None):
"""execute a query and return all results"""
with closing(self.db_conn.cursor()) as cur:
cur = self._execute(cur, query, attrs)
return cur.fetchall()
def _execute(self, cur, query, attrs, level=1):
"""execute a query, and in case of OperationalError (db restart)
reconnect to database. Recurses with increasig pause between tries"""
try:
if attrs is None:
cur.execute(query)
else:
cur.execute(query, attrs)
return cur
except psycopg2.OperationalError as error:
print("Sleeping: level %s (%s) @%s" % (
level, error, time.strftime("%Y%m%d %a %I:%m %p")
))
time.sleep(2 ** level)
self.db_conn = psycopg2.connect(self.dsn)
cur = self.db_conn.cursor() #how ugly is this?
return self._execute(cur, query, attrs, level+1)
def commit(self):
"""passes commit to db"""
self.db_conn.commit()

View file

@ -82,51 +82,48 @@ class Shop:
self.db.commit()
def _transaction(self, responsible = None, description = None):
with closing(self.db.cursor()) as cur:
cur.execute("INSERT INTO transactions (responsible, description) VALUES (%s, %s) RETURNING id",
[responsible.id if responsible else None, description])
transaction = cur.fetchone()[0]
transaction = self.db.execute_and_fetch("INSERT INTO transactions (responsible, description) VALUES (%s, %s) RETURNING id",
[responsible.id if responsible else None, description])
transaction = transaction[0]
return transaction
def credit_balance(self):
with closing(self.db.cursor()) as cur:
# We assume all debt accounts share a currency
sumselect = """
SELECT SUM(ts.amount)
FROM accounts AS a
LEFT JOIN transaction_splits AS ts ON a.id = ts.account
WHERE a.acctype = %s AND ts.side = %s
"""
cur.execute(sumselect, ["debt", 'debit'])
debit = cur.fetchone()[0] or 0
cur.execute(sumselect, ["debt", 'credit'])
credit = cur.fetchone()[0] or 0
# We assume all debt accounts share a currency
sumselect = """
SELECT SUM(ts.amount)
FROM accounts AS a
LEFT JOIN transaction_splits AS ts ON a.id = ts.account
WHERE a.acctype = %s AND ts.side = %s
"""
cur = self.db.execute_and_fetch(sumselect, ["debt", 'debit'])
debit = cur[0] or 0
credit = self.db.execute_and_fetch(sumselect, ["debt", 'credit'])
credit = credit[0] or 0
return debit - credit
def credit_negbalance_str(self):
return self.currency.str(-self.credit_balance())
def inventory_balance(self):
balance = 0
with closing(self.db.cursor()) as cur:
# Each inventory account has its own currency,
# so we just do this ugly iteration
cur.execute("SELECT id FROM accounts WHERE acctype = %s", ["inventory"])
for inventory in cur:
invid = inventory[0]
inv = Account.load(self.db, id = invid)
# FIXME: This is not correct as each instance of inventory
# might have been bought for a different price! Therefore,
# we need to replace the command below with a complex SQL
# statement that will... ugh, accounting is hard!
balance += inv.currency.convert(inv.balance(), self.currency)
# Each inventory account has its own currency,
# so we just do this ugly iteration
cur = self.db.execute_and_fetchall("SELECT id FROM accounts WHERE acctype = %s", ["inventory"])
for inventory in cur:
invid = inventory[0]
inv = Account.load(self.db, id = invid)
# FIXME: This is not correct as each instance of inventory
# might have been bought for a different price! Therefore,
# we need to replace the command below with a complex SQL
# statement that will... ugh, accounting is hard!
balance += inv.currency.convert(inv.balance(), self.currency)
return balance
def inventory_balance_str(self):
return self.currency.str(self.inventory_balance())
def account_list(self, acctype):
"""list all accounts (people or items, as per acctype)"""
accts = []
with closing(self.db.cursor()) as cur:
cur.execute("SELECT id FROM accounts WHERE acctype = %s ORDER BY name ASC", [acctype])
for inventory in cur:
accts += [ Account.load(self.db, id = inventory[0]) ]
cur = self.db.execute_and_fetchall("SELECT id FROM accounts WHERE acctype = %s ORDER BY name ASC", [acctype])
for inventory in cur:
accts += [ Account.load(self.db, id = inventory[0]) ]
return accts