Reflection should raise the proper Exception type when things are not found

[cpcloud]

Right now, when reflection fails, it's usually with a KeyError, but the other sqlalchemy dialects raise sa.exc.NoSuch<object>Error. I have code that depends on this exception being raised, which is how I found this issue.

I've got a PR in the works.

[cpcloud]

This was introduced in 1b911f2

[cpcloud]

It looks like only sa.exc.NoSuchTableError is relevant during reflection

[graingert]

Ah nice catch! Do you have the docs for this?

[cpcloud]

There's the docs for the exception: http://docs.sqlalchemy.org/en/rel_1_0/core/exceptions.html?highlight=nosuchtableerror#sqlalchemy.exc.NoSuchTableError

I'm looking for the usage docs (if any) right now.

[cpcloud]

I don't see anything here explicitly stating what exceptions should be raised in the case of not finding tables: http://docs.sqlalchemy.org/en/rel_1_0/core/reflection.html

I grepped through sqlalchemy core and found that indeed sybase, postgresql, and mysql all raise NoSuchTableError for specific functions (postgres has a get_table_oid method that raises it, mysql raises when doing a show create table or describe mytable statements, sybase has a similar mechanism to postgres).

For other dialects I think the error is raised here (in the Inspector class):

https://github.com/zzzeek/sqlalchemy/blob/master/lib/sqlalchemy/engine/reflection.py#L570-L571