4 files changed, 52 insertions, 1 deletions
diff --git a/lib/sqlalchemy/databases/mysql.py b/lib/sqlalchemy/databases/mysql.py
index 9e3f677d1..1eef6facb 100644
--- a/lib/sqlalchemy/databases/mysql.py
+++ b/lib/sqlalchemy/databases/mysql.py
@@ -175,7 +175,16 @@ class MySQLTableImpl(sql.TableImpl):
     rowid_column = property(lambda s: s._rowid_col())
 
 class MySQLCompiler(ansisql.ANSICompiler):
-    pass
+    def limit_clause(self, select):
+        text = ""
+        if select.limit is not None:
+            text +=  " \n LIMIT " + str(select.limit)
+        if select.offset is not None:
+            if select.limit is None:
+                # striaght from the MySQL docs, I kid you not
+                text += " \n LIMIT 18446744073709551615"
+            text += " OFFSET " + str(select.offset)
+        return text
         
 class MySQLSchemaGenerator(ansisql.ANSISchemaGenerator):
     def get_column_specification(self, column, override_pk=False, first_pk=False):
diff --git a/lib/sqlalchemy/databases/oracle.py b/lib/sqlalchemy/databases/oracle.py
index 58d533b10..93670729d 100644
--- a/lib/sqlalchemy/databases/oracle.py
+++ b/lib/sqlalchemy/databases/oracle.py
@@ -195,6 +195,28 @@ class OracleCompiler(ansisql.ANSICompiler):
                 self.bindparams[c.key] = None
         return ansisql.ANSICompiler.visit_insert(self, insert)
 
+    def visit_select(self, select):
+        """looks for LIMIT and OFFSET in a select statement, and if so tries to wrap it in a 
+        subquery with rownum criterion."""
+        if getattr(select, '_oracle_visit', False):
+            ansisql.ANSICompiler.visit_select(self, select)
+            return
+        if select.limit is not None or select.offset is not None:
+            select._oracle_visit = True
+            limitselect = select.select()
+            if select.limit is not None:
+                limitselect.append_whereclause("rownum<%d" % select.limit)
+            if select.offset is not None:
+                limitselect.append_whereclause("rownum>%d" % select.offset)
+            limitselect.accept_visitor(self)
+            self.strings[select] = self.strings[limitselect]
+            self.froms[select] = self.froms[limitselect]
+        else:
+            ansisql.ANSICompiler.visit_select(self, select)
+            
+    def limit_clause(self, select):
+        return ""
+
 class OracleSchemaGenerator(ansisql.ANSISchemaGenerator):
     def get_column_specification(self, column, override_pk=False, **kwargs):
         colspec = column.name
diff --git a/lib/sqlalchemy/databases/postgres.py b/lib/sqlalchemy/databases/postgres.py
index 5a3d6388a..531e8af03 100644
--- a/lib/sqlalchemy/databases/postgres.py
+++ b/lib/sqlalchemy/databases/postgres.py
@@ -240,6 +240,16 @@ class PGCompiler(ansisql.ANSICompiler):
             if c.sequence is not None and not c.sequence.optional:
                 self.bindparams[c.key] = None
         return ansisql.ANSICompiler.visit_insert(self, insert)
+
+    def limit_clause(self, select):
+        text = ""
+        if select.limit is not None:
+            text +=  " \n LIMIT " + str(select.limit)
+        if select.offset is not None:
+            if select.limit is None:
+                text += " \n LIMIT ALL"
+            text += " OFFSET " + str(select.offset)
+        return text
         
 class PGSchemaGenerator(ansisql.ANSISchemaGenerator):
     def get_column_specification(self, column, override_pk=False, **kwargs):
diff --git a/lib/sqlalchemy/databases/sqlite.py b/lib/sqlalchemy/databases/sqlite.py
index 23a9d0483..fc85d92ac 100644
--- a/lib/sqlalchemy/databases/sqlite.py
+++ b/lib/sqlalchemy/databases/sqlite.py
@@ -188,7 +188,17 @@ class SQLiteCompiler(ansisql.ANSICompiler):
     def __init__(self, *args, **params):
         params.setdefault('paramstyle', 'named')
         ansisql.ANSICompiler.__init__(self, *args, **params)
+    def limit_clause(self, select):
+        text = ""
+        if select.limit is not None:
+            text +=  " \n LIMIT " + str(select.limit)
+        if select.offset is not None:
+            if select.limit is None:
+                text += " \n LIMIT -1"
+            text += " OFFSET " + str(select.offset)
+        return text
 
+        
 class SQLiteSchemaGenerator(ansisql.ANSISchemaGenerator):
     def get_column_specification(self, column, override_pk=False, **kwargs):
         colspec = column.name + " " + column.type.get_col_spec()