The problem: find an rdbms-independent way to get a value with the specified key from a database using sqlalchemy! If the key doesn't exist, generate a new value and insert it to the table. In a multiuser+multiprocess environment... I have two ideas: 1st get it, if it returns None, then generate a new and insert, if it is unsuccessful (because of duplicate key) then get it again. 2nd: lock the table, get it, if returns None, then generate a new and insert The 2nd seems to be better, but I can't find an rdbms-independent solution for locking a table. (session.execute('lock ...') is inappropriate, because it uses sql directly) The 1st looks... khm... unprofessional. How can I solve this? Continue reading...
