i have similar thing, but by keeping an expression in my own terms and rendering into different things, like text, SQL, SA-expresion, etc. u define what is a variable, const, functor, overload all the operators, etc etc; then have a visitor that walks and translates (interprets) it into whatever one needs.
see the generic one http://dbcook.svn.sourceforge.net/viewvc/dbcook/trunk/dbcook/utik/expr.py and the above-into-SA-translator (automaticaly doing other stuff) http://dbcook.svn.sourceforge.net/viewvc/dbcook/trunk/dbcook/expression.py ciao svil On Wednesday 01 April 2009 21:18:23 Hinrich Winther wrote: > Maybe there is a better way of doing it. To be exact: > > I want to disassemble a given _BinaryExpression into basic elements > (a list of strings, arrays, integers ...) and reassemble it > somewhere else out of this basic elements. > > On 01.04.2009, at 18:14, Michael Bayer wrote: > > Hinrich Winther wrote: > >> Hi, > >> > >> I need to generate a sqlalchemy.sql.expression._BinaryExpression > >> by hand. So I looked into the docu and found that I need a left, > >> right and a operator. I am stuck at the left :) type() says it > >> is a sqlalchemy.sql.util.AnnotatedColumn. But I can't find the > >> class definition anywhere in sqlalchemy. Where is it defined? > > > > if you just say column('foo') == column('bar') (column is > > sqlalchemy.sql.column), you've got a _BinaryExpression. there > > shouldn't > > be a need to access _BinaryExpression directly. > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~----------~----~----~----~------~----~------~--~---
