Struct FixupLink 

pub struct FixupLink {
    pub parent_type_id: TypeId,
    pub parent_entry_idx: usize,
    pub child_type_id: TypeId,
    pub child_entry_indices: Vec<usize>,
    pub fk_target_type_id: TypeId,
    pub through_table: Option<String>,
    pub through_parent_fk_col: Option<String>,
    pub through_child_fk_col: Option<String>,
}

Records a parent→child association for post-INSERT FK fixup.

For one-to-many: after the principal is inserted and its PK backfilled, each child’s FK field is set to the principal’s PK via set_foreign_key.

For M2M: after both principal and child are inserted and their PKs backfilled, a join-table row is inserted via direct SQL.

Fields

parent_type_id: TypeId

parent_entry_idx: usize

child_type_id: TypeId

child_entry_indices: Vec<usize>

fk_target_type_id: TypeId

through_table: Option<String>

M2M only: the join table name. None for one-to-many.

through_parent_fk_col: Option<String>

through_child_fk_col: Option<String>