got column onupdate working

improvement to Function so that they can more easily be called standalone without having to throw them into a select().

1 files changed, 55 insertions, 7 deletions

diff --git a/lib/sqlalchemy/ansisql.py b/lib/sqlalchemy/ansisql.py
index 7c0002aa5..7b39d5358 100644
--- a/lib/sqlalchemy/ansisql.py
+++ b/lib/sqlalchemy/ansisql.py
@@ -15,6 +15,18 @@ from sqlalchemy.sql import *
 from sqlalchemy.util import *
 import string, re
 
+ANSI_FUNCS = HashSet([
+'CURRENT_TIME',
+'CURRENT_TIMESTAMP',
+'CURRENT_DATE',
+'LOCAL_TIME',
+'LOCAL_TIMESTAMP',
+'CURRENT_USER',
+'SESSION_USER',
+'USER'
+])
+
+
 def engine(**params):
     return ANSISQLEngine(**params)
 
@@ -57,6 +69,7 @@ class ANSICompiler(sql.Compiled):
         self.select_stack = []
         self.typemap = typemap or {}
         self.isinsert = False
+        self.isupdate = False
         self.bindtemplate = ":%s"
         if engine is not None:
             self.paramstyle = engine.paramstyle
@@ -89,7 +102,7 @@ class ANSICompiler(sql.Compiled):
                 self.strings[self.statement] = re.sub(match, getnum, self.strings[self.statement])
 
     def get_from_text(self, obj):
-        return self.froms[obj]
+        return self.froms.get(obj, None)
 
     def get_str(self, obj):
         return self.strings[obj]
@@ -158,6 +171,11 @@ class ANSICompiler(sql.Compiled):
         else:
             return parameters
     
+    def default_from(self):
+        """called when a SELECT statement has no froms, and no FROM clause is to be appended.  
+        gives Oracle a chance to tack on a "FROM DUAL" to the string output. """
+        return ""
+
     def visit_label(self, label):
         if len(self.select_stack):
             self.typemap.setdefault(label.name.lower(), label.obj.type)
@@ -211,7 +229,12 @@ class ANSICompiler(sql.Compiled):
             self.strings[list] = string.join([self.get_str(c) for c in list.clauses], ', ')
 
     def visit_function(self, func):
-        self.strings[func] = func.name + "(" + string.join([self.get_str(c) for c in func.clauses], ', ') + ")"
+        if len(self.select_stack):
+            self.typemap.setdefault(func.name, func.type)
+        if func.name.upper() in ANSI_FUNCS and not len(func.clauses):
+            self.strings[func] = func.name
+        else:
+            self.strings[func] = func.name + "(" + string.join([self.get_str(c) for c in func.clauses], ', ') + ")"
         
     def visit_compound_select(self, cs):
         text = string.join([self.get_str(c) for c in cs.selects], " " + cs.keyword + " ")
@@ -325,7 +348,9 @@ class ANSICompiler(sql.Compiled):
         if len(froms):
             text += " \nFROM "
             text += string.join(froms, ', ')
-
+        else:
+            text += self.default_from()
+            
         if whereclause is not None:
             t = self.get_str(whereclause)
             if t:
@@ -384,21 +409,33 @@ class ANSICompiler(sql.Compiled):
 
     def visit_insert_column_default(self, column, default):
         """called when visiting an Insert statement, for each column in the table that
-        contains a ColumnDefault object."""
+        contains a ColumnDefault object.  adds a blank 'placeholder' parameter so the 
+        Insert gets compiled with this column's name in its column and VALUES clauses."""
+        self.parameters.setdefault(column.key, None)
+
+    def visit_update_column_default(self, column, default):
+        """called when visiting an Update statement, for each column in the table that
+        contains a ColumnDefault object as an onupdate. adds a blank 'placeholder' parameter so the 
+        Update gets compiled with this column's name as one of its SET clauses."""
         self.parameters.setdefault(column.key, None)
         
     def visit_insert_sequence(self, column, sequence):
         """called when visiting an Insert statement, for each column in the table that
-        contains a Sequence object."""
+        contains a Sequence object.  Overridden by compilers that support sequences to place
+        a blank 'placeholder' parameter, so the Insert gets compiled with this column's
+        name in its column and VALUES clauses."""
         pass
     
     def visit_insert_column(self, column):
         """called when visiting an Insert statement, for each column in the table
-        that is a NULL insert into the table"""
+        that is a NULL insert into the table.  Overridden by compilers who disallow
+        NULL columns being set in an Insert where there is a default value on the column
+        (i.e. postgres), to remove the column from the parameter list."""
         pass
         
     def visit_insert(self, insert_stmt):
-        # set up a call for the defaults and sequences inside the table
+        # scan the table's columns for defaults that have to be pre-set for an INSERT
+        # add these columns to the parameter list via visit_insert_XXX methods
         class DefaultVisitor(schema.SchemaVisitor):
             def visit_column(s, c):
                 self.visit_insert_column(c)
@@ -424,6 +461,17 @@ class ANSICompiler(sql.Compiled):
         self.strings[insert_stmt] = text
 
     def visit_update(self, update_stmt):
+        # scan the table's columns for onupdates that have to be pre-set for an UPDATE
+        # add these columns to the parameter list via visit_update_XXX methods
+        class OnUpdateVisitor(schema.SchemaVisitor):
+            def visit_column_onupdate(s, cd):
+                self.visit_update_column_default(c, cd)
+        vis = OnUpdateVisitor()
+        for c in update_stmt.table.c:
+            if (isinstance(c, schema.SchemaItem) and (self.parameters is None or self.parameters.get(c.key, None) is None)):
+                c.accept_schema_visitor(vis)
+
+        self.isupdate = True
         colparams = self._get_colparams(update_stmt)
         def create_param(p):
             if isinstance(p, sql.BindParamClause):