bindparam name too long. Similar to #127

[zzzeek]

Originally reported by: Anonymous

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The name of bind parameter can get over 30 characters on occasion and Oracle does not like it. If label is already at 30 the source:/sqlalchemy/trunk/lib/sqlalchemy/orm/query.py line 29 will push it over the limit.

One could generate shorter label names in source:/sqlalchemy/trunk/lib/sqlalchemy/sql.py:

Index: sql.py

===================================================================

--- sql.py  (revision 1719)

+++ sql.py  (working copy)

@@ -1189,7 +1189,7 @@

             if self.table is not None and self.table.named_with_column():
                 self.__label =  self.table.name + "_" + self.name
                 if self.table.c.has_key(self.__label) or len(self.__label) >= 30:
-                    self.__label = self.__label[0:24](0:24) + "_" + hex(random.randint(0, 65535))[2:](2:)
+                    self.__label = self.__label[0:22](0:22) + "_" + hex(random.randint(0, 65535))[2:](2:)
             else:
                 self.__label = self.name
         return self.__label                                                  

or prepend something shorter that 'pk_':

Index: query.py

===================================================================

--- query.py    (revision 1719)

+++ query.py    (working copy)

@@ -26,7 +26,7 @@

         if not hasattr(self.mapper, '_get_clause'):
             _get_clause = sql.and_()
             for primary_key in self.mapper.pks_by_table[self.table](self.table):
-                _get_clause.clauses.append(primary_key == sql.bindparam("pk_"+primary_key._label, type=primary_key.type))
+                _get_clause.clauses.append(primary_key == sql.bindparam("p"+primary_key._label, type=primary_key.type))
             self.mapper._get_clause = _get_clause
         self._get_clause = self.mapper._get_clause
     def _get_session(self):
@@ -280,7 +280,7 @@

         i = 0
         params = {}
         for primary_key in self.mapper.pks_by_table[self.table](self.table):
-            params["pk_"+primary_key._label]("pk_"+primary_key._label) = ident[i](i)
+            params["p"+primary_key._label]("p"+primary_key._label) = ident[i](i)
             # if there are not enough elements in the given identifier, then 
             # use the previous identifier repeatedly.  this is a workaround for the issue 
             # in #185, where a mapper that uses joined table inheritance needs to specify

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• Bitbucket: https://bitbucket.org/zzzeek/sqlalchemy/issue/244

[zzzeek]

Original comment by Michael Bayer (Bitbucket: zzzeek, GitHub: zzzeek):

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the "pk_" prefix is superfluous; i removed it in changeset:1722.

if you try out the trunk with oracle, be advised there is a change to the workings of foreign keys with regards to table creation which I havent tested out yet (is probably fine).