2 # PostgreSQL database interface. Sort of like DBI(3) (Database
3 # independent interface for Perl).
5 # Mark Huang <mlhuang@cs.princeton.edu>
6 # Copyright (C) 2006 The Trustees of Princeton University
8 # $Id: PostgreSQL.py,v 1.10 2006/11/09 19:34:04 mlhuang Exp $
12 import psycopg2.extensions
13 psycopg2.extensions.register_type(psycopg2.extensions.UNICODE)
14 # UNICODEARRAY not exported yet
15 psycopg2.extensions.register_type(psycopg2._psycopg.UNICODEARRAY)
18 from types import StringTypes, NoneType
22 from pprint import pformat
24 from PLC.Debug import profile, log
25 from PLC.Faults import *
28 is8bit = re.compile("[\x80-\xff]").search
30 def unicast(typecast):
32 pgdb returns raw UTF-8 strings. This function casts strings that
33 appear to contain non-ASCII characters to unicode objects.
36 def wrapper(*args, **kwds):
37 value = typecast(*args, **kwds)
39 # pgdb always encodes unicode objects as UTF-8 regardless of
40 # the DB encoding (and gives you no option for overriding
41 # the encoding), so always decode 8-bit objects as UTF-8.
42 if isinstance(value, str) and is8bit(value):
43 value = unicode(value, "utf-8")
49 pgdb.pgdbTypeCache.typecast = unicast(pgdb.pgdbTypeCache.typecast)
52 def __init__(self, api):
55 # Initialize database connection
58 # Try UNIX socket first
59 self.db = psycopg2.connect(user = api.config.PLC_DB_USER,
60 password = api.config.PLC_DB_PASSWORD,
61 database = api.config.PLC_DB_NAME)
62 except psycopg2.OperationalError:
64 self.db = psycopg2.connect(user = api.config.PLC_DB_USER,
65 password = api.config.PLC_DB_PASSWORD,
66 database = api.config.PLC_DB_NAME,
67 host = api.config.PLC_DB_HOST,
68 port = api.config.PLC_DB_PORT)
69 self.db.set_client_encoding("UNICODE")
71 self.db = pgdb.connect(user = api.config.PLC_DB_USER,
72 password = api.config.PLC_DB_PASSWORD,
73 host = "%s:%d" % (api.config.PLC_DB_HOST, api.config.PLC_DB_PORT),
74 database = api.config.PLC_DB_NAME)
76 self.cursor = self.db.cursor()
78 (self.rowcount, self.description, self.lastrowid) = \
81 def quote(self, value):
83 Returns quoted version of the specified value.
86 # The pgdb._quote function is good enough for general SQL
87 # quoting, except for array types.
88 if isinstance(value, (list, tuple, set)):
89 return "ARRAY[%s]" % ", ".join(map, self.quote, value)
91 return pgdb._quote(value)
93 quote = classmethod(quote)
95 def param(self, name, value):
96 # None is converted to the unquoted string NULL
97 if isinstance(value, NoneType):
99 # True and False are also converted to unquoted strings
100 elif isinstance(value, bool):
102 elif isinstance(value, float):
104 elif not isinstance(value, StringTypes):
109 return '%(' + name + ')' + conversion
111 param = classmethod(param)
113 def begin_work(self):
114 # Implicit in pgdb.connect()
123 def do(self, query, params = None):
124 self.execute(query, params)
127 def last_insert_id(self, table_name, primary_key):
128 if isinstance(self.lastrowid, int):
129 sql = "SELECT %s FROM %s WHERE oid = %d" % \
130 (primary_key, table_name, self.lastrowid)
131 rows = self.selectall(sql, hashref = False)
137 def execute(self, query, params = None):
138 self.execute_array(query, (params,))
140 def execute_array(self, query, param_seq):
143 # psycopg2 requires %()s format for all parameters,
144 # regardless of type.
146 query = re.sub(r'(%\([^)]*\)|%)[df]', r'\1s', query)
148 cursor.executemany(query, param_seq)
149 (self.rowcount, self.description, self.lastrowid) = \
150 (cursor.rowcount, cursor.description, cursor.lastrowid)
156 uuid = commands.getoutput("uuidgen")
157 print >> log, "Database error %s:" % uuid
159 print >> log, "Query:"
161 print >> log, "Params:"
162 print >> log, pformat(param_seq[0])
163 raise PLCDBError("Please contact " + \
164 self.api.config.PLC_NAME + " Support " + \
165 "<" + self.api.config.PLC_MAIL_SUPPORT_ADDRESS + ">" + \
166 " and reference " + uuid)
168 def selectall(self, query, params = None, hashref = True, key_field = None):
170 Return each row as a dictionary keyed on field name (like DBI
171 selectrow_hashref()). If key_field is specified, return rows
172 as a dictionary keyed on the specified field (like DBI
173 selectall_hashref()).
175 If params is specified, the specified parameters will be bound
176 to the query (see PLC.DB.parameterize() and
177 pgdb.cursor.execute()).
180 self.execute(query, params)
181 rows = self.cursor.fetchall()
183 if hashref or key_field is not None:
184 # Return each row as a dictionary keyed on field name
185 # (like DBI selectrow_hashref()).
186 labels = [column[0] for column in self.description]
187 rows = [dict(zip(labels, row)) for row in rows]
189 if key_field is not None and key_field in labels:
190 # Return rows as a dictionary keyed on the specified field
191 # (like DBI selectall_hashref()).
192 return dict([(row[key_field], row) for row in rows])
196 def fields(self, table, notnull = None, hasdef = None):
198 Return the names of the fields of the specified table.
201 sql = "SELECT attname FROM pg_attribute, pg_class" \
202 " WHERE pg_class.oid = attrelid" \
203 " AND attnum > 0 AND relname = %(table)s"
205 if notnull is not None:
206 sql += " AND attnotnull is %(notnull)s"
208 if hasdef is not None:
209 sql += " AND atthasdef is %(hasdef)s"
211 rows = self.selectall(sql, locals(), hashref = False)
213 return [row[0] for row in rows]