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 1.13 2007/02/11 04:53:40 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 self.connection = None
58 if self.connection is None:
59 # (Re)initialize database connection
62 # Try UNIX socket first
63 self.connection = psycopg2.connect(user = self.api.config.PLC_DB_USER,
64 password = self.api.config.PLC_DB_PASSWORD,
65 database = self.api.config.PLC_DB_NAME)
66 except psycopg2.OperationalError:
68 self.connection = psycopg2.connect(user = self.api.config.PLC_DB_USER,
69 password = self.api.config.PLC_DB_PASSWORD,
70 database = self.api.config.PLC_DB_NAME,
71 host = self.api.config.PLC_DB_HOST,
72 port = self.api.config.PLC_DB_PORT)
73 self.connection.set_client_encoding("UNICODE")
75 self.connection = pgdb.connect(user = self.api.config.PLC_DB_USER,
76 password = self.api.config.PLC_DB_PASSWORD,
77 host = "%s:%d" % (api.config.PLC_DB_HOST, api.config.PLC_DB_PORT),
78 database = self.api.config.PLC_DB_NAME)
80 (self.rowcount, self.description, self.lastrowid) = \
83 return self.connection.cursor()
86 if self.connection is not None:
87 self.connection.close()
88 self.connection = None
90 def quote(self, value):
92 Returns quoted version of the specified value.
95 # The pgdb._quote function is good enough for general SQL
96 # quoting, except for array types.
97 if isinstance(value, (list, tuple, set)):
98 return "ARRAY[%s]" % ", ".join(map, self.quote, value)
100 return pgdb._quote(value)
102 quote = classmethod(quote)
104 def param(self, name, value):
105 # None is converted to the unquoted string NULL
106 if isinstance(value, NoneType):
108 # True and False are also converted to unquoted strings
109 elif isinstance(value, bool):
111 elif isinstance(value, float):
113 elif not isinstance(value, StringTypes):
118 return '%(' + name + ')' + conversion
120 param = classmethod(param)
122 def begin_work(self):
123 # Implicit in pgdb.connect()
127 self.connection.commit()
130 self.connection.rollback()
132 def do(self, query, params = None):
133 self.execute(query, params)
136 def last_insert_id(self, table_name, primary_key):
137 if isinstance(self.lastrowid, int):
138 sql = "SELECT %s FROM %s WHERE oid = %d" % \
139 (primary_key, table_name, self.lastrowid)
140 rows = self.selectall(sql, hashref = False)
146 def execute(self, query, params = None):
147 return self.execute_array(query, (params,))
149 def execute_array(self, query, param_seq):
150 cursor = self.cursor()
153 for params in param_seq:
155 print >> log, query % params
159 # psycopg2 requires %()s format for all parameters,
160 # regardless of type.
162 query = re.sub(r'(%\([^)]*\)|%)[df]', r'\1s', query)
164 cursor.executemany(query, param_seq)
165 (self.rowcount, self.description, self.lastrowid) = \
166 (cursor.rowcount, cursor.description, cursor.lastrowid)
172 uuid = commands.getoutput("uuidgen")
173 print >> log, "Database error %s:" % uuid
175 print >> log, "Query:"
177 print >> log, "Params:"
178 print >> log, pformat(param_seq[0])
179 raise PLCDBError("Please contact " + \
180 self.api.config.PLC_NAME + " Support " + \
181 "<" + self.api.config.PLC_MAIL_SUPPORT_ADDRESS + ">" + \
182 " and reference " + uuid)
186 def selectall(self, query, params = None, hashref = True, key_field = None):
188 Return each row as a dictionary keyed on field name (like DBI
189 selectrow_hashref()). If key_field is specified, return rows
190 as a dictionary keyed on the specified field (like DBI
191 selectall_hashref()).
193 If params is specified, the specified parameters will be bound
197 rows = self.execute(query, params).fetchall()
199 if hashref or key_field is not None:
200 # Return each row as a dictionary keyed on field name
201 # (like DBI selectrow_hashref()).
202 labels = [column[0] for column in self.description]
203 rows = [dict(zip(labels, row)) for row in rows]
205 if key_field is not None and key_field in labels:
206 # Return rows as a dictionary keyed on the specified field
207 # (like DBI selectall_hashref()).
208 return dict([(row[key_field], row) for row in rows])
212 def fields(self, table, notnull = None, hasdef = None):
214 Return the names of the fields of the specified table.
217 if hasattr(self, 'fields_cache'):
218 if self.fields_cache.has_key((table, notnull, hasdef)):
219 return self.fields_cache[(table, notnull, hasdef)]
221 self.fields_cache = {}
223 sql = "SELECT attname FROM pg_attribute, pg_class" \
224 " WHERE pg_class.oid = attrelid" \
225 " AND attnum > 0 AND relname = %(table)s"
227 if notnull is not None:
228 sql += " AND attnotnull is %(notnull)s"
230 if hasdef is not None:
231 sql += " AND atthasdef is %(hasdef)s"
233 rows = self.selectall(sql, locals(), hashref = False)
235 self.fields_cache[(table, notnull, hasdef)] = [row[0] for row in rows]
237 return self.fields_cache[(table, notnull, hasdef)]