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DB::Xoos cpan:YNOTO last updated on 2019-03-22



Xoos is an ORM designed for convenience and ease of use, it is modeled after DBIx::* if you're into that kind of thing already (note: some concepts and names have deviated).

(This module was originally named Koos until my friends in Israel let me know that that's a vulgar word in Arabic)


what works



Below is a minimum viable model setup for your app. Xoos does not create the table for you, that is up to you.


use DB::Xoos::SQLite;

my DB::Xoos::SQLite $d .=new;


my $customer-model = $d.model('Customer');
my $new-customer   = $;
$'xyz co');
$new-customer.update; # runs an insert because this is a new row

my $xyz = ${ name => { 'like' => '%xyz%' } }).first;
$xyz.rate( $xyz.rate * 2 ); #twice the rate!
$xyz.update; # UPDATEs the database

my $xyz-orders = $xyz.orders.count;


use DB::Xoos::Model;
unit class Model::Customer does DB::Xoos::Model['customer'];

has @.columns = [
  id => {
    type           => 'integer',
    nullable       => False,
    is-primary-key => True,
    auto-increment => 1,
  name => {
    type           => 'text',
  rate => {
    type => 'integer',

has @.relations = [
  orders => { :has-many, :model<Order>, :relate(id => 'customer_id') },

role DB::Xoos::Model

What is a model? A model is essentially a table in your database. Your ::Model::X is pretty barebones, in this module you'll defined @.columns and @.relations (if there are any relations).


use DB::Xoos::Model;
# the second argument below is optional and also accepts a type.
# if the arg is omitted then it attempts to auto load ::Row::Customer
# if it fails to auto load then it uses an anonymous Row and adds convenience methods to that
unit class X::Model::Customer does DB::Xoos::Model['customer', 'X::Row::Customer']; 

has @.columns = [
  id => {
    type           => 'integer',
    nullable       => False,
    is-primary-key => True,
    auto-increment => 1,
  name => {
    type           => 'text',
  contact => {
    type => 'text',
  country => {
    type => 'text',

has @.relations = [
  orders => { :has-many, :model<Order>, :relate(id => 'customer_id') },
  open_orders => { :has-many, :model<Order>, :relate(id => 'customer_id', '+status' => 'open') },
  completed_orders => { :has-many, :model<Order>, :relate(id => 'customer_id', '+status' => 'closed') },

# down here you can have convenience methods

method delete-all { #never do this in real life
  die '.delete-all disabled in prod or if %*ENV{in-prod} not defined'
    if !defined %*ENV{in-prod} || so %*ENV{in-prod};
  my $s ={ id => { '>' => -1 } });
  !so $s.count;

In this example we're creating a customer model with columns id, name, contact, country and relations with specific filter criteria. You may notice the +status => 'open' on the open_orders relationship, the + here indicates it's a filter on the original table.


class :: does DB::Xoos::Model['table-name', 'Optional String or Type'];

Here you can see the role accepts one or two parameters, the first is the DB table name, the latter is a String or Type of the row you'd like to use for this model. If no row is found then Xoos will create a generic row and add helper methods for you using the model's column data.


A list of columns in the table. It is highly recommended you have one is-primary-key or .update will have unexpected results.


This accepts a list of key values, the key defining the accessor name, the later a hash describing the relationship. :has-one and :has-many are both used to dictate whether a Xoos model returns an inflated object (:has-one) or a filterable object (:has-many).


search(%filter?, %options?)

Creates a new filterable model and returns that. Every subsequent call to .search will add to the existing filters and options the best it can.


my $customer = $dbo.model('Customer').search({
  name => { like => '%bozo%' }, 
}, {
  order-by => [ created_date => 'DESC', 'customer_name' ], 
# later on ...
my $geo-filtered-customers = ${ country => 'usa' });
# $geo-filtered-customers effective filter is:
#   {
#      name => { like => '%bozo%' },
#      country => 'usa',
#   }


Returns all rows from query (an array of inflated ::Row::XYZ). Providing %filter is the same as doing .search(%filter).all and is provided only for convenience.

.first(%filter?, :$next = False)

Returns the first row (again, inflated ::Row::XYZ) and caches the prepared statement (this is destroyed and ignored if $next is falsey)


Same as calling .first(%filter, :next)


Returns the result of a select count for the current filter selection. Providing %filter results in .search(%filter).count


Deletes all rows matching criteria. Providing %filter results in .search(%filter).delete


Creates a new row with %field-data.

Convenience methods

Xoos::Model inheritance allows you to have convenience methods, these methods can act on whatever the current set of filters is.

Consider the following:

Convenience model definition:

class X::Model::Customer does Xoos::Model['customer'];

# columns and relations

method remove-closed-orders {

Later in your code:

my $customers = $dbo.model('Customer');

my $all-customers    = ${ id => { '>' => -1 } });
my $single-customers = ${ id => 5 });

# this removes all orders for customers with an id > -1
# this removes all orders for customers with id = 5

role Xoos::Row

A role to apply to your ::Row::Customer. If there is no ::Row::Customer a generic row is created using the column and relationship data specified in the corresponding Model and this file is only really necessary if you want to add convenience methods.

When a class :: does Xoos::Row, it receives the info from the model and adds the methods for setting/getting field data.

With the model definition above:

my $invoice-model = $dbo.model('invoice');
my $invoice = ${
  customer_id => $,
  amount      => 400,
});  # this $invoice is NOT in the database until .update

my $old-amount = $invoice.amount; # = 400
$invoice.amount($invoice.amount * 2);
my $new-amount = $invoice.amount; # = 800


If there is a collision in the naming conventions between your model and the row then you'll need to use [set|get]-column



Duplicates the row omitting the is-primary-key field so the subsequent .save results in a new row rather than updating


Returns the current field data for the row as a hash. If there has been unsaved updates to fields then it returns those values instead of what is in the database. You can determine whether the row has field-changes with is-dirty

.set-column(Str $key, $value)

Updates the field data for the column (not stored in database until .update is called). If you want to .wrap a field setter for a certain key, wrap this and filter for the key

.get-column(Str $key)

Retrieves the value for $key with any field changes having priority over data in database, use .is-dirty

.get-relation(Str $column, :%spec?)

It is recommended any Model with a relationship name that conflicts and causes no convenience method to be generated be renamed, but use this if you must. $customer.orders is calling essentially $customer.get-relation('orders'). Do not provide %spec unless you know what you're doing.


Saves the row in the database. If the field with a positive is-primary-key is set then it runs and UPDATE ... statement, otherwise it INSERT ...s and updates the Row's is-primary-key field. Ensure you set one field with is-primary-key

Field validation

It's just this easy:

has @.columns = [
  phone => {
    type     => 'text',
    validate => sub ($new-value) {
      # return Falsey value here for validation to fail
      #   Truthy value will cause validation to succeed