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 1.1 2006/09/06 15:36:07 mlhuang Exp $
12 from types import StringTypes, NoneType
15 from pprint import pformat
17 from PLC.Debug import profile, log
18 from PLC.Faults import *
21 def __init__(self, api):
24 # Initialize database connection
25 self.db = pgdb.connect(user = api.config.PLC_DB_USER,
26 password = api.config.PLC_DB_PASSWORD,
27 host = "%s:%d" % (api.config.PLC_DB_HOST, api.config.PLC_DB_PORT),
28 database = api.config.PLC_DB_NAME)
29 self.cursor = self.db.cursor()
31 (self.rowcount, self.description, self.lastrowid) = \
34 def quote(self, params):
36 Returns quoted version(s) of the specified parameter(s).
39 # pgdb._quote functions are good enough for general SQL quoting
40 if hasattr(params, 'has_key'):
41 params = pgdb._quoteitem(params)
42 elif isinstance(params, list) or isinstance(params, tuple):
43 params = map(pgdb._quote, params)
45 params = pgdb._quote(params)
49 quote = classmethod(quote)
51 def param(self, name, value):
52 # None is converted to the unquoted string NULL
53 if isinstance(value, NoneType):
55 # True and False are also converted to unquoted strings
56 elif isinstance(value, bool):
58 elif isinstance(value, float):
60 elif not isinstance(value, StringTypes):
65 return '%(' + name + ')' + conversion
67 param = classmethod(param)
70 # Implicit in pgdb.connect()
79 def do(self, query, params = None):
80 self.execute(query, params)
83 def last_insert_id(self):
86 def execute(self, query, params = None):
87 self.execute_array(query, (params,))
89 def execute_array(self, query, param_seq):
92 cursor.executemany(query, param_seq)
93 (self.rowcount, self.description, self.lastrowid) = \
94 (cursor.rowcount, cursor.description, cursor.lastrowid)
95 except pgdb.DatabaseError, e:
97 uuid = commands.getoutput("uuidgen")
98 print >> log, "Database error %s:" % uuid
100 print >> log, "Query:"
102 print >> log, "Params:"
103 print >> log, pformat(param_seq[0])
104 raise PLCDBError("Please contact " + \
105 self.api.config.PLC_NAME + " Support " + \
106 "<" + self.api.config.PLC_MAIL_SUPPORT_ADDRESS + ">" + \
107 " and reference " + uuid)
109 def selectall(self, query, params = None, hashref = True, key_field = None):
111 Return each row as a dictionary keyed on field name (like DBI
112 selectrow_hashref()). If key_field is specified, return rows
113 as a dictionary keyed on the specified field (like DBI
114 selectall_hashref()).
116 If params is specified, the specified parameters will be bound
117 to the query (see PLC.DB.parameterize() and
118 pgdb.cursor.execute()).
121 self.execute(query, params)
122 rows = self.cursor.fetchall()
125 # Return each row as a dictionary keyed on field name
126 # (like DBI selectrow_hashref()).
127 labels = [column[0] for column in self.description]
128 rows = [dict(zip(labels, row)) for row in rows]
130 if key_field is not None and key_field in labels:
131 # Return rows as a dictionary keyed on the specified field
132 # (like DBI selectall_hashref()).
133 return dict([(row[key_field], row) for row in rows])
137 def fields(self, table):
139 Return the names of the fields of the specified table.
142 rows = self.selectall("SELECT attname FROM pg_attribute, pg_class" \
143 " WHERE pg_class.oid = attrelid" \
144 " AND attnum > 0 AND relname = %(table)s",
148 return [row[0] for row in rows]