.. change::
    :tags: sql, reflection
    :tickets: 4741

    The "NO ACTION" keyword for foreign key "ON UPDATE" is now considered to be
    the default cascade for a foreign key on all supporting backends (SQlite,
    MySQL, PostgreSQL) and when detected is not included in the reflection
    dictionary; this is already the behavior for PostgreSQL and MySQL for all
    previous SQLAlchemy versions in any case.   The "RESTRICT" keyword is
    positively stored when detected; PostgreSQL does report on this keyword,
    and MySQL as of version 8.0 does as well.  On earlier MySQL versions, it is
    not reported by the database.
