On Feb 23, 2010, at 5:23 PM, David Bolen wrote: > But various attempts to use these queries in a filter() portion of the > original query always result ArgumentError exception that "filter() > argument must be of type sqlalchemy.sql.ClauseElement or string" > > I figured I'm missing some magic method to permit turning "att == reg" > into a ClauseElemnt somehow, but my attempts so far haven't worked. So > for the moment I'm supplying the additional sub-query clause as pure > text.
if the issue is that you have a query(), and you like to say somequery.filter(q == "x"), you'd turn query() into a "subquery" (i.e. an alisaed SQLAlchemy expression object) using q.subquery(), and then into a "scalar" subquery using as_scalar(), which means the select() construct now behaves like a column. as_scalar() is also available directly on a select() construct. some background on as_scalar() is presented from the SQL expression side of things at http://www.sqlalchemy.org/docs/sqlexpression.html#scalar-selects . -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalch...@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.
