svn keywords
[plcapi.git] / PLC / PostgreSQL.py
index 495435e..101cfe6 100644 (file)
@@ -5,7 +5,8 @@
 # Mark Huang <mlhuang@cs.princeton.edu>
 # Copyright (C) 2006 The Trustees of Princeton University
 #
-# $Id: PostgreSQL.py,v 1.11 2006/12/04 19:10:47 mlhuang Exp $
+# $Id$
+# $URL$
 #
 
 import psycopg2
@@ -52,33 +53,42 @@ class PostgreSQL:
     def __init__(self, api):
         self.api = api
         self.debug = False
+#        self.debug = True
+        self.connection = None
 
-        # Initialize database connection
-        if psycopg2:
-            try:
-                # Try UNIX socket first
-                self.db = psycopg2.connect(user = api.config.PLC_DB_USER,
-                                           password = api.config.PLC_DB_PASSWORD,
-                                           database = api.config.PLC_DB_NAME)
-            except psycopg2.OperationalError:
-                # Fall back on TCP
-                self.db = psycopg2.connect(user = api.config.PLC_DB_USER,
-                                           password = api.config.PLC_DB_PASSWORD,
-                                           database = api.config.PLC_DB_NAME,
-                                           host = api.config.PLC_DB_HOST,
-                                           port = api.config.PLC_DB_PORT)
-            self.db.set_client_encoding("UNICODE")
-        else:
-            self.db = pgdb.connect(user = api.config.PLC_DB_USER,
-                                   password = api.config.PLC_DB_PASSWORD,
-                                   host = "%s:%d" % (api.config.PLC_DB_HOST, api.config.PLC_DB_PORT),
-                                   database = api.config.PLC_DB_NAME)
-
-        self.cursor = self.db.cursor()
+    def cursor(self):
+        if self.connection is None:
+            # (Re)initialize database connection
+            if psycopg2:
+                try:
+                    # Try UNIX socket first
+                    self.connection = psycopg2.connect(user = self.api.config.PLC_DB_USER,
+                                                       password = self.api.config.PLC_DB_PASSWORD,
+                                                       database = self.api.config.PLC_DB_NAME)
+                except psycopg2.OperationalError:
+                    # Fall back on TCP
+                    self.connection = psycopg2.connect(user = self.api.config.PLC_DB_USER,
+                                                       password = self.api.config.PLC_DB_PASSWORD,
+                                                       database = self.api.config.PLC_DB_NAME,
+                                                       host = self.api.config.PLC_DB_HOST,
+                                                       port = self.api.config.PLC_DB_PORT)
+                self.connection.set_client_encoding("UNICODE")
+            else:
+                self.connection = pgdb.connect(user = self.api.config.PLC_DB_USER,
+                                               password = self.api.config.PLC_DB_PASSWORD,
+                                               host = "%s:%d" % (api.config.PLC_DB_HOST, api.config.PLC_DB_PORT),
+                                               database = self.api.config.PLC_DB_NAME)
 
         (self.rowcount, self.description, self.lastrowid) = \
                         (None, None, None)
 
+        return self.connection.cursor()
+
+    def close(self):
+        if self.connection is not None:
+            self.connection.close()
+            self.connection = None
+
     def quote(self, value):
         """
         Returns quoted version of the specified value.
@@ -116,15 +126,25 @@ class PostgreSQL:
         pass
 
     def commit(self):
-        self.db.commit()
+        self.connection.commit()
 
     def rollback(self):
-        self.db.rollback()
+        self.connection.rollback()
 
     def do(self, query, params = None):
-        self.execute(query, params)
+        cursor = self.execute(query, params)
+        cursor.close()
         return self.rowcount
 
+    def next_id(self, table_name, primary_key):
+       sequence = "%(table_name)s_%(primary_key)s_seq" % locals()      
+       sql = "SELECT nextval('%(sequence)s')" % locals()
+       rows = self.selectall(sql, hashref = False)
+       if rows: 
+           return rows[0][0]
+               
+       return None 
+
     def last_insert_id(self, table_name, primary_key):
         if isinstance(self.lastrowid, int):
             sql = "SELECT %s FROM %s WHERE oid = %d" % \
@@ -135,25 +155,44 @@ class PostgreSQL:
 
         return None
 
+    # modified for psycopg2-2.0.7 
+    # executemany is undefined for SELECT's
+    # see http://www.python.org/dev/peps/pep-0249/
+    # accepts either None, a single dict, a tuple of single dict - in which case it execute's
+    # or a tuple of several dicts, in which case it executemany's
     def execute(self, query, params = None):
-        self.execute_array(query, (params,))
 
-    def execute_array(self, query, param_seq):
-        cursor = self.cursor
+        cursor = self.cursor()
         try:
-            if self.debug:
-                for params in param_seq:
-                    if params:
-                        print >> log, query % params
-                    else:
-                        print >> log, query
 
             # psycopg2 requires %()s format for all parameters,
             # regardless of type.
+            # this needs to be done carefully though as with pattern-based filters
+            # we might have percents embedded in the query
+            # so e.g. GetPersons({'email':'*fake*'}) was resulting in .. LIKE '%sake%'
             if psycopg2:
                 query = re.sub(r'(%\([^)]*\)|%)[df]', r'\1s', query)
-
-            cursor.executemany(query, param_seq)
+            # rewrite wildcards set by Filter.py as '***' into '%'
+            query = query.replace ('***','%')
+
+            if not params:
+                if self.debug:
+                    print >> log,'execute0',query
+                cursor.execute(query)
+            elif isinstance(params,dict):
+                if self.debug:
+                    print >> log,'execute-dict: params',params,'query',query%params
+                cursor.execute(query,params)
+            elif isinstance(params,tuple) and len(params)==1:
+                if self.debug:
+                    print >> log,'execute-tuple',query%params[0]
+                cursor.execute(query,params[0])
+            else:
+                param_seq=(params,)
+                if self.debug:
+                    for params in param_seq:
+                        print >> log,'executemany',query%params
+                cursor.executemany(query, param_seq)
             (self.rowcount, self.description, self.lastrowid) = \
                             (cursor.rowcount, cursor.description, cursor.lastrowid)
         except Exception, e:
@@ -167,12 +206,14 @@ class PostgreSQL:
             print >> log, "Query:"
             print >> log, query
             print >> log, "Params:"
-            print >> log, pformat(param_seq[0])
+            print >> log, pformat(params)
             raise PLCDBError("Please contact " + \
                              self.api.config.PLC_NAME + " Support " + \
                              "<" + self.api.config.PLC_MAIL_SUPPORT_ADDRESS + ">" + \
                              " and reference " + uuid)
 
+        return cursor
+
     def selectall(self, query, params = None, hashref = True, key_field = None):
         """
         Return each row as a dictionary keyed on field name (like DBI
@@ -181,13 +222,13 @@ class PostgreSQL:
         selectall_hashref()).
 
         If params is specified, the specified parameters will be bound
-        to the query (see PLC.DB.parameterize() and
-        pgdb.cursor.execute()).
+        to the query.
         """
 
-        self.execute(query, params)
-        rows = self.cursor.fetchall()
-
+        cursor = self.execute(query, params)
+        rows = cursor.fetchall()
+        cursor.close()
+        self.commit()
         if hashref or key_field is not None:
             # Return each row as a dictionary keyed on field name
             # (like DBI selectrow_hashref()).