sort of muscling this out, mysql a PITA

1 files changed, 47 insertions, 7 deletions

diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py
index 8d7f2aab9..b77591912 100644
--- a/lib/sqlalchemy/sql/compiler.py
+++ b/lib/sqlalchemy/sql/compiler.py
@@ -985,15 +985,46 @@ class SQLCompiler(engine.Compiled):
 
         return text
 
-    def visit_update(self, update_stmt):
+    def update_limit_clause(self, update_stmt):
+        return None
+
+    def update_tables_clause(self, update_stmt, from_table, extra_froms, **kw):
+        return self.preparer.format_table(from_table)
+
+    def update_from_clause(self, update_stmt, from_table, extra_froms, **kw):
+        return "FROM " + ', '.join(t._compiler_dispatch(self, asfrom=True, **kw) for t in extra_froms)
+
+    def should_render_table_with_col_in_update(self, update_stmt, from_table, extra_froms):
+        return False
+
+    def visit_update(self, update_stmt, **kw):
         self.stack.append({'from': set([update_stmt.table])})
 
         self.isupdate = True
-        colparams = self._get_colparams(update_stmt)
 
-        text = "UPDATE " + self.preparer.format_table(update_stmt.table)
+        if update_stmt._whereclause is not None:
+            extra_froms = set(update_stmt._whereclause._from_objects).\
+                            difference([update_stmt.table])
+        else:
+            extra_froms = set()
+
+        colparams = self._get_colparams(update_stmt, extra_froms)
+
+        #for c in colparams:
+        #    if hasattr(c[1], '_from_objects'):
+        #        extra_froms.update(c[1]._from_objects)
 
-        text += ' SET ' + \
+        text = "UPDATE " + self.update_tables_clause(update_stmt, update_stmt.table, extra_froms, **kw)
+
+        if self.should_render_table_with_col_in_update(update_stmt, update_stmt.table, extra_froms):
+            text += ' SET ' + \
+                    ', '.join(
+                            self.visit_column(c[0]) + 
+                            '=' + c[1]
+                          for c in colparams
+                    )
+        else:
+            text += ' SET ' + \
                 ', '.join(
                         self.preparer.quote(c[0].name, c[0].quote) + 
                         '=' + c[1]
@@ -1006,9 +1037,18 @@ class SQLCompiler(engine.Compiled):
                 text += " " + self.returning_clause(
                                     update_stmt, update_stmt._returning)
 
+        if extra_froms:
+            extra_from_text = self.update_from_clause(update_stmt, update_stmt.table, extra_froms, **kw)
+            if extra_from_text:
+                text += " " + extra_from_text
+
         if update_stmt._whereclause is not None:
             text += " WHERE " + self.process(update_stmt._whereclause)
 
+        limit_clause = self.update_limit_clause(update_stmt)
+        if limit_clause:
+            text += " " + limit_clause
+
         if self.returning and not self.returning_precedes_values:
             text += " " + self.returning_clause(
                                     update_stmt, update_stmt._returning)
@@ -1024,7 +1064,7 @@ class SQLCompiler(engine.Compiled):
         return bindparam._compiler_dispatch(self)
 
 
-    def _get_colparams(self, stmt):
+    def _get_colparams(self, stmt, extra_tables=None):
         """create a set of tuples representing column/string pairs for use
         in an INSERT or UPDATE statement.
 
@@ -1100,7 +1140,7 @@ class SQLCompiler(engine.Compiled):
                     (
                         implicit_returning or 
                         not postfetch_lastrowid or 
-                        c is not stmt.table._autoincrement_column
+                        c is not t._autoincrement_column
                     ):
 
                     if implicit_returning:
@@ -1127,7 +1167,7 @@ class SQLCompiler(engine.Compiled):
                             self.returning.append(c)
                     else:
                         if c.default is not None or \
-                            c is stmt.table._autoincrement_column and (
+                            c is t._autoincrement_column and (
                                 self.dialect.supports_sequences or
                                 self.dialect.preexecute_autoincrement_sequences
                             ):