from sqlobject.dbconnection import DBAPI
import re
from sqlobject import col
from sqlobject import sqlbuilder
from sqlobject.converters import registerConverter
class PostgresConnection(DBAPI):
supportTransactions = True
dbName = 'postgres'
schemes = [dbName, 'postgresql']
def __init__(self, dsn=None, host=None, port=None, db=None,
user=None, password=None, backend='psycopg', unicodeCols=False,
**kw):
backends = backend
for backend in backends.split(','):
backend = backend.strip()
if not backend:
continue
try:
if backend == 'psycopg2':
import psycopg2 as psycopg
elif backend == 'psycopg1':
import psycopg
elif backend == 'psycopg':
try:
import psycopg2 as psycopg
except ImportError:
import psycopg
elif backend == 'pygresql':
import pgdb
self.module = pgdb
else:
raise ValueError('Unknown PostgreSQL backend "%s", expected psycopg2, psycopg1 or pygresql' % backend)
except ImportError:
pass
else:
break
else:
raise ImportError('Cannot find a PostgreSQL backend, tried %s' % backends)
if backend.startswith('psycopg'):
self.module = psycopg
# Register a converter for psycopg Binary type.
registerConverter(type(psycopg.Binary('')),
PsycoBinaryConverter)
self.user = user
self.host = host
self.port = port
self.db = db
self.password = password
self.dsn_dict = dsn_dict = {}
if host:
dsn_dict["host"] = host
if port:
if backend == 'pygresql':
dsn_dict["host"] = "%s:%d" % (host, port)
else:
if psycopg.__version__.split('.')[0] == '1':
dsn_dict["port"] = str(port)
else:
dsn_dict["port"] = port
if db:
dsn_dict["database"] = db
if user:
dsn_dict["user"] = user
if password:
dsn_dict["password"] = password
self.use_dsn = dsn is not None
if dsn is None:
if backend == 'pygresql':
dsn = ''
if host:
dsn += host
dsn += ':'
if db:
dsn += db
dsn += ':'
if user:
dsn += user
dsn += ':'
if password:
dsn += password
else:
dsn = []
if db:
dsn.append('dbname=%s' % db)
if user:
dsn.append('user=%s' % user)
if password:
dsn.append('password=%s' % password)
if host:
dsn.append('host=%s' % host)
if port:
dsn.append('port=%d' % port)
dsn = ' '.join(dsn)
self.dsn = dsn
self.unicodeCols = unicodeCols
self.schema = kw.pop('schema', None)
if "charset" in kw:
self.dbEncoding = kw.pop("charset")
else:
self.dbEncoding = None
DBAPI.__init__(self, **kw)
def connectionFromURI(cls, uri):
user, password, host, port, path, args = cls._parseURI(uri)
path = path.strip('/')
if (host is None) and path.count('/'): # Non-default unix socket
path_parts = path.split('/')
host = '/' + '/'.join(path_parts[:-1])
path = path_parts[-1]
return cls(host=host, port=port, db=path, user=user, password=password, **args)
connectionFromURI = classmethod(connectionFromURI)
def _setAutoCommit(self, conn, auto):
# psycopg2 does not have an autocommit method.
if hasattr(conn, 'autocommit'):
conn.autocommit(auto)
def makeConnection(self):
try:
if self.use_dsn:
conn = self.module.connect(self.dsn)
else:
conn = self.module.connect(**self.dsn_dict)
except self.module.OperationalError, e:
raise self.module.OperationalError("%s; used connection string %r" % (e, self.dsn))
if self.autoCommit:
# psycopg2 does not have an autocommit method.
if hasattr(conn, 'autocommit'):
conn.autocommit(1)
c = conn.cursor()
if self.schema:
c.execute("SET search_path TO " + self.schema)
dbEncoding = self.dbEncoding
if dbEncoding:
c.execute("SET client_encoding TO %s" % dbEncoding)
return conn
def _queryInsertID(self, conn, soInstance, id, names, values):
table = soInstance.sqlmeta.table
idName = soInstance.sqlmeta.idName
sequenceName = soInstance.sqlmeta.idSequence or \
'%s_%s_seq' % (table, idName)
c = conn.cursor()
if id is None:
c.execute("SELECT NEXTVAL('%s')" % sequenceName)
id = c.fetchone()[0]
names = [idName] + names
values = [id] + values
q = self._insertSQL(table, names, values)
if self.debug:
self.printDebug(conn, q, 'QueryIns')
c.execute(q)
if self.debugOutput:
self.printDebug(conn, id, 'QueryIns', 'result')
return id
def _queryAddLimitOffset(cls, query, start, end):
if not start:
return "%s LIMIT %i" % (query, end)
if not end:
return "%s OFFSET %i" % (query, start)
return "%s LIMIT %i OFFSET %i" % (query, end-start, start)
_queryAddLimitOffset = classmethod(_queryAddLimitOffset)
def createColumn(self, soClass, col):
return col.postgresCreateSQL()
def createReferenceConstraint(self, soClass, col):
return col.postgresCreateReferenceConstraint()
def createIndexSQL(self, soClass, index):
return index.postgresCreateIndexSQL(soClass)
def createIDColumn(self, soClass):
key_type = {int: "SERIAL", str: "TEXT"}[soClass.sqlmeta.idType]
return '%s %s PRIMARY KEY' % (soClass.sqlmeta.idName, key_type)
def dropTable(self, tableName, cascade=False):
self.query("DROP TABLE %s %s" % (tableName,
cascade and 'CASCADE' or ''))
def joinSQLType(self, join):
return 'INT NOT NULL'
def tableExists(self, tableName):
result = self.queryOne("SELECT COUNT(relname) FROM pg_class WHERE relname = %s"
% self.sqlrepr(tableName))
return result[0]
def addColumn(self, tableName, column):
self.query('ALTER TABLE %s ADD COLUMN %s' %
(tableName,
column.postgresCreateSQL()))
def delColumn(self, sqlmeta, column):
self.query('ALTER TABLE %s DROP COLUMN %s' % (sqlmeta.table, column.dbName))
def columnsFromSchema(self, tableName, soClass):
keyQuery = """
SELECT pg_catalog.pg_get_constraintdef(oid) as condef
FROM pg_catalog.pg_constraint r
WHERE r.conrelid = %s::regclass AND r.contype = 'f'"""
colQuery = """
SELECT a.attname,
pg_catalog.format_type(a.atttypid, a.atttypmod), a.attnotnull,
(SELECT substring(d.adsrc for 128) FROM pg_catalog.pg_attrdef d
WHERE d.adrelid=a.attrelid AND d.adnum = a.attnum)
FROM pg_catalog.pg_attribute a
WHERE a.attrelid =%s::regclass
AND a.attnum > 0 AND NOT a.attisdropped
ORDER BY a.attnum"""
primaryKeyQuery = """
SELECT pg_index.indisprimary,
pg_catalog.pg_get_indexdef(pg_index.indexrelid)
FROM pg_catalog.pg_class c, pg_catalog.pg_class c2,
pg_catalog.pg_index AS pg_index
WHERE c.relname = %s
AND c.oid = pg_index.indrelid
AND pg_index.indexrelid = c2.oid
AND pg_index.indisprimary
"""
keyData = self.queryAll(keyQuery % self.sqlrepr(tableName))
keyRE = re.compile(r"\((.+)\) REFERENCES (.+)\(")
keymap = {}
for (condef,) in keyData:
match = keyRE.search(condef)
if match:
field, reftable = match.groups()
keymap[field] = reftable.capitalize()
primaryData = self.queryAll(primaryKeyQuery % self.sqlrepr(tableName))
primaryRE = re.compile(r'CREATE .*? USING .* \((.+?)\)')
primaryKey = None
for isPrimary, indexDef in primaryData:
match = primaryRE.search(indexDef)
assert match, "Unparseable contraint definition: %r" % indexDef
assert primaryKey is None, "Already found primary key (%r), then found: %r" % (primaryKey, indexDef)
primaryKey = match.group(1)
assert primaryKey, "No primary key found in table %r" % tableName
if primaryKey.startswith('"'):
assert primaryKey.endswith('"')
primaryKey = primaryKey[1:-1]
colData = self.queryAll(colQuery % self.sqlrepr(tableName))
results = []
if self.unicodeCols:
client_encoding = self.queryOne("SHOW client_encoding")[0]
for field, t, notnull, defaultstr in colData:
if field == primaryKey:
continue
if keymap.has_key(field):
colClass = col.ForeignKey
kw = {'foreignKey': soClass.sqlmeta.style.dbTableToPythonClass(keymap[field])}
name = soClass.sqlmeta.style.dbColumnToPythonAttr(field)
if name.endswith('ID'):
name = name[:-2]
kw['name'] = name
else:
colClass, kw = self.guessClass(t)
if self.unicodeCols and colClass is col.StringCol:
colClass = col.UnicodeCol
kw['dbEncoding'] = client_encoding
kw['name'] = soClass.sqlmeta.style.dbColumnToPythonAttr(field)
kw['dbName'] = field
kw['notNone'] = notnull
if defaultstr is not None:
kw['default'] = self.defaultFromSchema(colClass, defaultstr)
elif not notnull:
kw['default'] = None
results.append(colClass(**kw))
return results
def guessClass(self, t):
if t.count('point'): # poINT before INT
return col.StringCol, {}
elif t.count('int'):
return col.IntCol, {}
elif t.count('varying') or t.count('varchar'):
if '(' in t:
return col.StringCol, {'length': int(t[t.index('(')+1:-1])}
else: # varchar without length in Postgres means any length
return col.StringCol, {}
elif t.startswith('character('):
return col.StringCol, {'length': int(t[t.index('(')+1:-1]),
'varchar': False}
elif t.count('float') or t.count('real') or t.count('double'):
return col.FloatCol, {}
elif t == 'text':
return col.StringCol, {}
elif t.startswith('timestamp'):
return col.DateTimeCol, {}
elif t.startswith('datetime'):
return col.DateTimeCol, {}
elif t.startswith('date'):
return col.DateCol, {}
elif t.startswith('bool'):
return col.BoolCol, {}
elif t.startswith('bytea'):
return col.BLOBCol, {}
else:
return col.Col, {}
def defaultFromSchema(self, colClass, defaultstr):
"""
If the default can be converted to a python constant, convert it.
Otherwise return is as a sqlbuilder constant.
"""
if colClass == col.BoolCol:
if defaultstr == 'false':
return False
elif defaultstr == 'true':
return True
return getattr(sqlbuilder.const, defaultstr)
def _createOrDropDatabase(self, op="CREATE"):
# We have to connect to *some* database, so we'll connect to
# template1, which is a common open database.
# @@: This doesn't use self.use_dsn or self.dsn_dict
if self.backend == 'pygresql':
dsn = '%s:template1:%s:%s' % (
self.host or '', self.user or '', self.password or '')
else:
dsn = 'dbname=template1'
if self.user:
dsn += ' user=%s' % self.user
if self.password:
dsn += ' password=%s' % self.password
if self.host:
dsn += ' host=%s' % self.host
conn = self.module.connect(dsn)
cur = conn.cursor()
# We must close the transaction with a commit so that
# the CREATE DATABASE can work (which can't be in a transaction):
cur.execute('COMMIT')
cur.execute('%s DATABASE %s' % (op, self.db))
cur.close()
conn.close()
def createEmptyDatabase(self):
self._createOrDropDatabase()
def dropDatabase(self):
self._createOrDropDatabase(op="DROP")
# Converter for psycopg Binary type.
def PsycoBinaryConverter(value, db):
assert db == 'postgres'
return str(value)
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