From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Thu, 14 Jun 2007 18:17:05 +0000 (+0000)
Subject:  - result sets from CRUD operations close their underlying cursor immediately.
X-Git-Tag: rel_0_4_6~200
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=baba8281df184b59afec2a26ca4bb69dec029437;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

 - result sets from CRUD operations close their underlying cursor immediately.
    will also autoclose the connection if defined for the operation; this
    allows more efficient usage of connections for successive CRUD operations
    with less chance of "dangling connections".
---

diff --git a/CHANGES b/CHANGES
index dab2fd67aa..9a4d9e2093 100644
--- a/CHANGES
+++ b/CHANGES
@@ -31,6 +31,10 @@
   - result.last_inserted_ids() should return a list that is identically
     sized to the primary key constraint of the table.  values that were 
     "passively" created and not available via cursor.lastrowid will be None.
+  - result sets from CRUD operations close their underlying cursor immediately.
+    will also autoclose the connection if defined for the operation; this 
+    allows more efficient usage of connections for successive CRUD operations
+    with less chance of "dangling connections".
   - long-identifier detection fixed to use > rather than >= for 
     max ident length [ticket:589]
   - fixed bug where selectable.corresponding_column(selectable.c.col)
diff --git a/lib/sqlalchemy/databases/postgres.py b/lib/sqlalchemy/databases/postgres.py
index 0622958262..7573b5a8d7 100644
--- a/lib/sqlalchemy/databases/postgres.py
+++ b/lib/sqlalchemy/databases/postgres.py
@@ -134,11 +134,11 @@ def descriptor():
 
 class PGExecutionContext(default.DefaultExecutionContext):
 
-    def is_select(self):
-        return re.match(r'SELECT', self.statement.lstrip(), re.I) and not re.search(r'FOR UPDATE\s*$', self.statement, re.I)
-    
+    def _is_server_side(self):
+        return self.dialect.server_side_cursors and self.is_select() and not re.search(r'FOR UPDATE(?: NOWAIT)?\s*$', self.statement, re.I)
+        
     def create_cursor(self):
-        if self.dialect.server_side_cursors and self.is_select():
+        if self._is_server_side():
             # use server-side cursors:
             # http://lists.initd.org/pipermail/psycopg/2007-January/005251.html
             ident = "c" + hex(random.randint(0, 65535))[2:]
@@ -147,7 +147,7 @@ class PGExecutionContext(default.DefaultExecutionContext):
             return self.connection.connection.cursor()
 
     def get_result_proxy(self):
-        if self.dialect.server_side_cursors and self.is_select():
+        if self._is_server_side():
             return base.BufferedRowResultProxy(self)
         else:
             return base.ResultProxy(self)
diff --git a/lib/sqlalchemy/databases/sqlite.py b/lib/sqlalchemy/databases/sqlite.py
index 0d5fc45e9e..53525582f6 100644
--- a/lib/sqlalchemy/databases/sqlite.py
+++ b/lib/sqlalchemy/databases/sqlite.py
@@ -141,6 +141,9 @@ class SQLiteExecutionContext(default.DefaultExecutionContext):
         if self.compiled.isinsert:
             self._last_inserted_ids = [self.cursor.lastrowid] + self._last_inserted_ids[1:]
         super(SQLiteExecutionContext, self).post_exec()
+
+    def is_select(self):
+        return re.match(r'SELECT|PRAGMA', self.statement.lstrip(), re.I) is not None
         
 class SQLiteDialect(ansisql.ANSIDialect):
     
diff --git a/lib/sqlalchemy/engine/base.py b/lib/sqlalchemy/engine/base.py
index e7eb108b53..b1e1ee5cc9 100644
--- a/lib/sqlalchemy/engine/base.py
+++ b/lib/sqlalchemy/engine/base.py
@@ -861,10 +861,20 @@ class ResultProxy(object):
         self.closed = False
         self.cursor = context.cursor
         self.__echo = logging.is_debug_enabled(context.engine.logger)
-        self._init_metadata()
-        
-    rowcount = property(lambda s:s.context.get_rowcount())
-    connection = property(lambda s:s.context.connection)
+        if context.is_select():
+            self._init_metadata()
+            self._rowcount = None
+        else:
+            self._rowcount = context.get_rowcount()
+            self.close()
+            
+    connection = property(lambda self:self.context.connection)
+    def _get_rowcount(self):
+        if self._rowcount is not None:
+            return self._rowcount
+        else:
+            return self.context.get_rowcount()
+    rowcount = property(_get_rowcount)
     
     def _init_metadata(self):
         if hasattr(self, '_ResultProxy__props'):
diff --git a/lib/sqlalchemy/engine/default.py b/lib/sqlalchemy/engine/default.py
index 19dd623bfe..cde8ee0981 100644
--- a/lib/sqlalchemy/engine/default.py
+++ b/lib/sqlalchemy/engine/default.py
@@ -191,7 +191,7 @@ class DefaultExecutionContext(base.ExecutionContext):
                 return proc(params)
                 
     def is_select(self):
-        return re.match(r'SELECT', self.statement.lstrip(), re.I)
+        return re.match(r'SELECT', self.statement.lstrip(), re.I) is not None
 
     def create_cursor(self):
         return self.connection.connection.cursor()