On Sun, Nov 26, 2017 at 9:39 PM, <jens.troe...@gmail.com> wrote: > Thank you, Mike! > > I’ve tried to implement what we talked about above, but had a few problems. > First, I was unable to use MySQLdb because of compilation errors; instead > I’ve used pymysql for a while now. When I tried to run the test code from > your previous answer I received a SQL syntax error near WHERE. It looks like > the FROM is missing.
OK I don't recall what conditions MySQL needs "FROM dual" can you share with me: 1. the full version of MySQL 2. the output of "SHOW VARIABLES LIKE '%SQL_MODE%' 3. stack trace + error message > > As for “fails” I was mistaken. The conditional insert should always succeed, > but may not insert a row into the table. While this maintains data > consistency, it’s not quite what I need. It’ll do for now though. > > My current working solution is the following hack which I need to revisit > again later: > > # Create a proxy object to return to the caller. > token = Token( > id=uuid4(), > user=user_id, > client_sig=sigstring, > ) > # If I don't expunge then the token is automatically added/inserted? > # I thought I'd always have to dbsession.add(). > dbsession.expunge(token) > > # Now issue the SQL statement much like the on from my initial question. > sql = ( > "INSERT INTO tokens(id, user_id, client_sig) " > "SELECT '" + token.id + "', '" + token.user_id + "', '" + > token.client_sig + "' " > "FROM dual " > "WHERE NOT EXISTS " > "(SELECT * FROM tokens WHERE user_id='" + token.user_id + "' AND > client_sig='" + token.client_sig + "')" > ) > dbsession.execute(sql) > > # Return the proxy object to the Pyramid view function. > return token > > I realize that this is a poor solution because the returned proxy object may > in rare cases not represent what's committed to the db. However, that's > easier to handle than committing a duplicate. I would also prefer SQLA > functions over raw SQL code. > > Jens > > -- > SQLAlchemy - > The Python SQL Toolkit and Object Relational Mapper > > http://www.sqlalchemy.org/ > > To post example code, please provide an MCVE: Minimal, Complete, and > Verifiable Example. See http://stackoverflow.com/help/mcve for a full > description. > --- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sqlalchemy+unsubscr...@googlegroups.com. > To post to this group, send email to sqlalchemy@googlegroups.com. > Visit this group at https://groups.google.com/group/sqlalchemy. > For more options, visit https://groups.google.com/d/optout. -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
