# Todo

- Add is_valid() method to connection & connection_impl
- Read in entity fields
- Add special handling for update in backends
- Add ODBC/SQL Server backend


Fetch eager strategies
======================

ONE TO ONE/MANY
*person*             *address*
- has one address    - belongs to person

=> join "address" on "person.id" == "address.person_id"

*address*             *person*
- belongs to person   - has one address

=> join "person" on "address.person_id" == "person.id"

*book*               *author*
- belongs to author  - has many books

- => join "author" on "book.author_id" == "author.id"

HAS MANY TO ONE (WITHOUT RELATION TABLE)

*author*             *book*
- has many books     - belongs to author

- => join "book" on "author.id" == "book.author_id"

if "has many" type has primary key & field "author_id"
if table name belongs to entity template type?

HAS MANY TO MANY (WITHOUT RELATION TABLE)

*student*            *student_course*           *course*
- has many courses   - belongs to student
                     - belongs to course        - has many students

=> join "student_course" on "student.id" == "student_course.student_id"
   join "student_course" on "course.id" == "student_course.course_id"

if has many type hasn't primary key (is relation table)