Am 29.11.2017 um 17:16 schrieb Mike Bayer: > On Wed, Nov 29, 2017 at 11:12 AM, Mike Bayer <mike...@zzzcomputing.com> wrote: >> On Wed, Nov 29, 2017 at 3:37 AM, <lars.lied...@kit.edu> wrote: >>> Hello everybody, >>> >>> I am writing some piece of code, which should not exit unforseen in the best >>> case, at least it should write to a log file what went wrong (e.g. Database >>> not reachable, etc). So I tried figuring out, which Exceptions would be >>> possibly thrown by SQLAlchemy: > let me also add that if "unforseen exit" is the issue, you're mostly > going to look for the SQL-related errors thrown by the driver which on > the SQLAlchemy side are the DBAPIError classes, however even in that > case, some of those errors mean "couldn't connect to the database", > which could be mis-configuration OR the database is down, others can > mean "SQL is wrong". So even then it's hard to know ahead of time > what conditions can be caught and handled vs. which ones mean the > program needs to be re-configured and restarted. Of course, In my case it will be a call from the crontab starting my process regularly, I just wanted my process not to exit without writing it to the logfile what the problem was with a "nicely" formatted message, so the logfiles can be checked for certain messages in ELK. So I think I can limit them down to if there is an error connecting to the database because the queries are pretty much fixed and only differ in which element(s) I query and of course I have to make sure that the configuration is correct. > > > > >> the exception classes are documented at: >> >> http://docs.sqlalchemy.org/en/latest/core/exceptions.html >> http://docs.sqlalchemy.org/en/latest/orm/exceptions.html >> >> i will note that while the ORM exceptions are linked from the front >> page of the docs, the Core ones are not, you need to go into the full >> table of contents to see it >> (http://docs.sqlalchemy.org/en/latest/contents.html). >> >> as to the exact codepath that can raise these, it depends on the >> exception. The docstrings for the exceptions themselves can of >> course have some additional detail as to what kinds of operations >> might raise them. Though generic ones like "InvalidRequestError" or >> "ArgumentError" are thrown in dozens of places wherever the library is >> asked to do something that doesn't make sense or function arguments >> that don't make sense are detected. Thank you very much, I must have not seen the Link. >> >>> The first thing I did was googling for how to find out which Exceptions >>> could be thrown in Python. The answers I found on Stack Overflow etc. were >>> like "You simply don't", "This is Python, dumbass, you can't predict which >>> are thrown so don't even try" or "Just write tests until you found them all" >>> and "Just catch the general Exception class." >>> So I tried looking at the SQLAlchemy Documentation to see if there is >>> something written about when something goes wrong, but still no luck. >>> Before I started digging into the code I thought I'd ask here first >>> >>> So is there any hint to know which Exceptions could be thrown by SQLAlchemy? >>> The error cases I could think of were mostly wrrors while connecting to the >>> database or having errors in queries. I would totally be willing to help >>> with documenting at a certain point but even for this I need to know if I >>> just did't find any documentation for this and if you consider this as >>> neccessary. I feel that it is neccessary for me not just to kill the process >>> with maybe a stack trace on stdout. >>> >>> >>> Cheers >>> >>> Lars Liedtke >>> >>> -- >>> 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.
-- Karlsruher Institut für Technologie (KIT) Steinbuch Centre für Computing (SCC) B.Sc. Lars Liedtke Administrator bwSync&Share Hermann-von-Helmholtz-Platz 1 Gebaäude 441/Raum 233 D-76344 Eggenstein-Leopoldshafen Telefon: +49 721 608-28875 Fax: +49 721 608-24972 E-Mail: Lars.Liedtke∂kit.edu Web: www.scc.kit.edu KIT – Die Forschungsuniversität in der Helmholtz-Gemeinschaft Das KIT ist seit 2010 als familiengerechte Hochschule zertifiziert. -- 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.
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