fix schema migration hooks (partial)
SQL Server requires some additional steps to alter columns
(index drop and restore, etc...) and this in turn requires
passing a connection on the DB to find out the indexes.
Also partially fix an issue where the null_allowed value was
not correctly computed. Still some problems in there
(see https://www.logilab.net/cwo/ticket/1109558)
[MESSAGES CONTROL]
disable-msg = C0301
[VARIABLES]
# Enable / disable this checker
enable-variables = yes
additional-builtins = _, display_name
[BASIC]
required-attributes=
attr-rgx = (w|[a-z_][a-z0-9_]{2,30})
variable-rgx = (w|[a-z_][a-z0-9_]{2,30})$
argument-rgx = (w|[a-z_][a-z0-9_]{2,30})$
[TYPECHECK]
generated-members=debug,info,notice,warning,error,critical,exception