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 1.11 2006/12/04 19:10:47 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):
56 # Initialize database connection
59 # Try UNIX socket first
60 self.db = psycopg2.connect(user = api.config.PLC_DB_USER,
61 password = api.config.PLC_DB_PASSWORD,
62 database = api.config.PLC_DB_NAME)
63 except psycopg2.OperationalError:
65 self.db = psycopg2.connect(user = api.config.PLC_DB_USER,
66 password = api.config.PLC_DB_PASSWORD,
67 database = api.config.PLC_DB_NAME,
68 host = api.config.PLC_DB_HOST,
69 port = api.config.PLC_DB_PORT)
70 self.db.set_client_encoding("UNICODE")
72 self.db = pgdb.connect(user = api.config.PLC_DB_USER,
73 password = api.config.PLC_DB_PASSWORD,
74 host = "%s:%d" % (api.config.PLC_DB_HOST, api.config.PLC_DB_PORT),
75 database = api.config.PLC_DB_NAME)
77 self.cursor = self.db.cursor()
79 (self.rowcount, self.description, self.lastrowid) = \
82 def quote(self, value):
84 Returns quoted version of the specified value.
87 # The pgdb._quote function is good enough for general SQL
88 # quoting, except for array types.
89 if isinstance(value, (list, tuple, set)):
90 return "ARRAY[%s]" % ", ".join(map, self.quote, value)
92 return pgdb._quote(value)
94 quote = classmethod(quote)
96 def param(self, name, value):
97 # None is converted to the unquoted string NULL
98 if isinstance(value, NoneType):
100 # True and False are also converted to unquoted strings
101 elif isinstance(value, bool):
103 elif isinstance(value, float):
105 elif not isinstance(value, StringTypes):
110 return '%(' + name + ')' + conversion
112 param = classmethod(param)
114 def begin_work(self):
115 # Implicit in pgdb.connect()
124 def do(self, query, params = None):
125 self.execute(query, params)
128 def last_insert_id(self, table_name, primary_key):
129 if isinstance(self.lastrowid, int):
130 sql = "SELECT %s FROM %s WHERE oid = %d" % \
131 (primary_key, table_name, self.lastrowid)
132 rows = self.selectall(sql, hashref = False)
138 def execute(self, query, params = None):
139 self.execute_array(query, (params,))
141 def execute_array(self, query, param_seq):
145 for params in param_seq:
147 print >> log, query % params
151 # psycopg2 requires %()s format for all parameters,
152 # regardless of type.
154 query = re.sub(r'(%\([^)]*\)|%)[df]', r'\1s', query)
156 cursor.executemany(query, param_seq)
157 (self.rowcount, self.description, self.lastrowid) = \
158 (cursor.rowcount, cursor.description, cursor.lastrowid)
164 uuid = commands.getoutput("uuidgen")
165 print >> log, "Database error %s:" % uuid
167 print >> log, "Query:"
169 print >> log, "Params:"
170 print >> log, pformat(param_seq[0])
171 raise PLCDBError("Please contact " + \
172 self.api.config.PLC_NAME + " Support " + \
173 "<" + self.api.config.PLC_MAIL_SUPPORT_ADDRESS + ">" + \
174 " and reference " + uuid)
176 def selectall(self, query, params = None, hashref = True, key_field = None):
178 Return each row as a dictionary keyed on field name (like DBI
179 selectrow_hashref()). If key_field is specified, return rows
180 as a dictionary keyed on the specified field (like DBI
181 selectall_hashref()).
183 If params is specified, the specified parameters will be bound
184 to the query (see PLC.DB.parameterize() and
185 pgdb.cursor.execute()).
188 self.execute(query, params)
189 rows = self.cursor.fetchall()
191 if hashref or key_field is not None:
192 # Return each row as a dictionary keyed on field name
193 # (like DBI selectrow_hashref()).
194 labels = [column[0] for column in self.description]
195 rows = [dict(zip(labels, row)) for row in rows]
197 if key_field is not None and key_field in labels:
198 # Return rows as a dictionary keyed on the specified field
199 # (like DBI selectall_hashref()).
200 return dict([(row[key_field], row) for row in rows])
204 def fields(self, table, notnull = None, hasdef = None):
206 Return the names of the fields of the specified table.
209 if hasattr(self, 'fields_cache'):
210 if self.fields_cache.has_key((table, notnull, hasdef)):
211 return self.fields_cache[(table, notnull, hasdef)]
213 self.fields_cache = {}
215 sql = "SELECT attname FROM pg_attribute, pg_class" \
216 " WHERE pg_class.oid = attrelid" \
217 " AND attnum > 0 AND relname = %(table)s"
219 if notnull is not None:
220 sql += " AND attnotnull is %(notnull)s"
222 if hasdef is not None:
223 sql += " AND atthasdef is %(hasdef)s"
225 rows = self.selectall(sql, locals(), hashref = False)
227 self.fields_cache[(table, notnull, hasdef)] = [row[0] for row in rows]
229 return self.fields_cache[(table, notnull, hasdef)]