Question

i am looking for opinions if the following problem maybe has a better/different/common solution:

---

I have a database for products which contains the names of the products in english (the default language of this application) and i need translations of the names if available.

Currently i have this setup:

A product table

CREATE TABLE products (   id serial NOT NULL,   'name' character varying(255) NOT NULL,   CONSTRAINT products_pkey PRIMARY KEY (id) ) 

and a product localization table

CREATE TABLE products_l10n (   product_id serial NOT NULL,   'language' character(2) NOT NULL,   'name' character varying(255) NOT NULL,   CONSTRAINT products_l10n_pkey PRIMARY KEY (product_id, language),   CONSTRAINT products_l10n_product_id_fkey FOREIGN KEY (product_id)       REFERENCES products (id) MATCH SIMPLE       ON UPDATE CASCADE ON DELETE CASCADE ) 

and i use the following query to retrieve a list of localized products (german in this case) with fallback to the default english names:

SELECT p.id, COALESCE(pl.name, p.name)  from products p LEFT  JOIN products_l10n pl ON p.id = pl.product_id AND language = 'de'; 

The SQL code is in postgres dialect. Data is stored as UTF-8.

Answer 1

Looks good to me. The one thing I might change is the way you handle languages: that should probably be a separate table. Thus, you would have:

CREATE TABLE products_l10n (   product_id serial NOT NULL,   language_id int NOT NULL,   'name' character varying(255) NOT NULL,   CONSTRAINT products_l10n_pkey PRIMARY KEY (product_id, language),   CONSTRAINT products_l10n_product_id_fkey FOREIGN KEY (product_id)       REFERENCES products (id) MATCH SIMPLE       ON UPDATE CASCADE ON DELETE CASCADE   CONSTRAINT products_l10n_language_id_fkey FOREIGN KEY (language_id)       REFERENCES languages (id) MATCH SIMPLE       ON UPDATE CASCADE ON DELETE CASCADE )  CREATE TABLE languages )   id serial not null   'language' character(2) NOT NULL ) 

Besides that, I think you’ve got just about the best possible solution.