Constant ON_DELETE 

pub const ON_DELETE: ColumnMarker;

Specifies the ON DELETE action for foreign key references.

Example

#[column(references = User::id, on_delete = CASCADE)]
user_id: i32,

Supported Actions

• CASCADE: Delete rows that reference the deleted row
• SET_NULL: Set the column to NULL when referenced row is deleted
• SET_DEFAULT: Set the column to its default value
• RESTRICT: Prevent deletion if referenced
• NO_ACTION: Similar to RESTRICT (default)

See: https://sqlite.org/foreignkeys.html#fk_actions