A database table may split into several tables sharing the same primary key. This is done because

• the original table got too many columns
• A group of columns in the table is optional
• You want to control access with Toql roles.

Partial tables are supported with joins.

# #![allow(unused_variables)]
#fn main() {
use toql::prelude::Toql;

#[derive(Toql)]
#[toql(auto_key)]
struct Question {
    #[toql(key)]
    id: u64,

    text: String,

    #[toql(join(columns(self="id", other="question_id"), partial_table))]
    details: Option<QuestionDetails>
}

#[derive(Toql)]
struct QuestionDetails {
    #[toql(key)]
    question_id: u64,
    
    font: String
}
#}

In the example above Question and QuestionDetails share the same values for primary keys.This is what patial_table says. So for a question with id = 42 there is a question_details with question_id = 42.

Inserts will always insert all partial tables too, whenever a path list asks to insert the base table (Question).

Also it will avoid to insert a non existing foreign key: If QuestionDetails was regular join (without partial_table) insert would try to set a (non existing) column details_id with the value of the primary key of Questiondetails. This would be correct for regular joins, but fails on partial tables.

Updates have the same behaviour when inserting new merges and for loading partial_table has no effect.