Merge pull request #37 from blue-yonder/hoffmann-patch-executemanny-u…

…pdate

set executemany to false for update statements if there is only one parameter fixes #36

CHANGES.md

@@ -1,5 +1,8 @@
 # HEAD
 
+# 0.9.2
+* change execute behaviour for updates fixes #36
+
 # 0.9.1
 * support for DISTRIBUTE BY table constraints
 

sqlalchemy_exasol/base.py

@@ -404,6 +404,8 @@ def pre_exec(self):
             self.statement = db_query
             self.parameters = [[]]
 
+        if self.isupdate and len(self.parameters) == 1:
+            self.executemany = False
 
 class EXADialect(default.DefaultDialect):
     name = 'exasol'

test/test_update.py

@@ -0,0 +1,125 @@
+from sqlalchemy import *
+from sqlalchemy import testing
+from sqlalchemy.dialects import mysql
+from sqlalchemy.engine import default
+from sqlalchemy.testing import AssertsCompiledSQL, eq_, fixtures
+from sqlalchemy.testing.schema import Table, Column
+
+
+class _UpdateTestBase(object):
+
+    @classmethod
+    def define_tables(cls, metadata):
+        Table('mytable', metadata,
+              Column('myid', Integer),
+              Column('name', String(30)),
+              Column('description', String(50)))
+        Table('myothertable', metadata,
+              Column('otherid', Integer),
+              Column('othername', String(30)))
+        Table('users', metadata,
+              Column('id', Integer, primary_key=True,
+                     test_needs_autoincrement=True),
+              Column('name', String(30), nullable=False))
+        Table('addresses', metadata,
+              Column('id', Integer, primary_key=True,
+                     test_needs_autoincrement=True),
+              Column('user_id', None, ForeignKey('users.id')),
+              Column('name', String(30), nullable=False),
+              Column('email_address', String(50), nullable=False))
+        Table('dingalings', metadata,
+              Column('id', Integer, primary_key=True,
+                     test_needs_autoincrement=True),
+              Column('address_id', None, ForeignKey('addresses.id')),
+              Column('data', String(30)))
+
+    @classmethod
+    def fixtures(cls):
+        return dict(
+            users=(
+                ('id', 'name'),
+                (7, 'jack'),
+                (8, 'ed'),
+                (9, 'fred'),
+                (10, 'chuck')
+            ),
+            addresses = (
+                ('id', 'user_id', 'name', 'email_address'),
+                (1, 7, 'x', 'jack@bean.com'),
+                (2, 8, 'x', 'ed@wood.com'),
+                (3, 8, 'x', 'ed@bettyboop.com'),
+                (4, 8, 'x', 'ed@lala.com'),
+                (5, 9, 'x', 'fred@fred.com')
+            ),
+            dingalings = (
+                ('id', 'address_id', 'data'),
+                (1, 2, 'ding 1/2'),
+                (2, 5, 'ding 2/5')
+            ),
+        )
+
+
+
+
+class UpdateTest(_UpdateTestBase, fixtures.TablesTest):
+    __backend__ = True
+
+    def test_update_simple(self):
+        """test simple update and assert that exasol returns the right rowcount"""
+        users =  self.tables.users
+        result = testing.db.execute(users.update().values(name="peter").where(users.c.id == 10))
+        expected = [
+                (7, 'jack'),
+                (8, 'ed'),
+                (9, 'fred'),
+                (10, 'peter')
+                ]
+        assert result.rowcount ==  1
+        self._assert_users(users, expected)
+
+    def test_update_simple_multiple_rows_rowcount(self):
+        """test simple update and assert that exasol returns the right rowcount"""
+        users =  self.tables.users
+        result = testing.db.execute(users.update().values(name="peter").where(users.c.id >= 9))
+        expected = [
+                (7, 'jack'),
+                (8, 'ed'),
+                (9, 'peter'),
+                (10, 'peter')
+                ]
+        assert result.rowcount == 2 
+        self._assert_users(users, expected)
+
+    def test_update_executemany(self):
+        """test that update with executemany work as well, but rowcount
+        is undefined for executemany updates"""
+        users =  self.tables.users
+
+        stmt = users.update().\
+                where(users.c.name == bindparam('oldname')).\
+                values(name=bindparam('newname'))
+
+        values = [{'oldname':'jack', 'newname':'jack2'},
+                  {'oldname':'fred', 'newname':'fred2'}]
+
+        result = testing.db.execute(stmt, values)
+        expected = [ 
+                (7, 'jack2'),
+                (8, 'ed'),
+                (9, 'fred2'),
+                (10, 'chuck')
+                ]  
+        assert result.rowcount ==  -1
+        self._assert_users(users, expected)
+
+
+    def _assert_addresses(self, addresses, expected):
+        stmt = addresses.select().order_by(addresses.c.id)
+        eq_(testing.db.execute(stmt).fetchall(), expected)
+
+
+    def _assert_users(self, users, expected):
+        stmt = users.select().order_by(users.c.id)
+        eq_(testing.db.execute(stmt).fetchall(), expected)
+
+