Function insert 

pub async fn insert<A>(
    db: &Db,
    active: A,
) -> Result<<<A as ActiveModelTrait>::Entity as EntityTrait>::Model, DataError>
where
    A: ActiveModelTrait + ActiveModelBehavior + Send,
    <A::Entity as EntityTrait>::Model: IntoActiveModel<A>,

Insert a new row from an ActiveModel. Returns the inserted model with database-generated fields (auto-increment PKs, defaults) populated.

Errors

Returns DataError::Database if the insert fails (e.g. a uniqueness constraint violation surfaces as a SeaORM DbErr).