query/Todo.md

48 lines
1.3 KiB
Markdown

# 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)