postgresql - Creating rule for update view sql error -

i trying create updaetable view.

i have table product, category, product_has_category.

create table "category" ( "category_id" serial not null, "name" varchar(15) not null, "description" varchar(150) not null, primary key("category_id") );  create table "product" ( "product_id" serial not null, "name" varchar(20) not null, "price" int4 not null, "description" varchar(200), "country_of_origin" varchar(20) not null, primary key("product_id") );   create table "product_has_category" ( "nmid" serial not null, "product_id" int4 not null, "category_id" int4 not null );  alter table "product_has_category"  add constraint "ref_product_has_category_to_product" foreign key ("product_product_id") references "product"("product_id") match simple on delete cascade on update cascade not deferrable; 

and here view selects products, price , categories:

create view products_with_categories select product.name product_name, product.price, category.name     category product, category, product_has_category product_has_category.product_id = product.product_id , product_has_category.category_id = category.category_id order product_name; 

i want view updatable , created rule:

create rule prod_cat_upd on update products_with_categories  instead  update product     set product.name=new.product.name  product.name=old.product.name 

and got following error:

invalid reference from-clause entry table "product" hint: there entry table "product", cannot referenced part of query.

i can not understand error means , how solve problem.

try syntax create rule, refer more documentation

create rule prod_cat_upd on update products_with_categories  instead  update product         set name=new.name name=old.name 

i created 2 sql fiddle sample table

1) sample sql fiddle solution, provide :- working fine

    create table shoelace_data (     sl_name    text,          -- primary key     sl_avail   integer,       -- available number of pairs     sl_color   text,          -- shoelace color     sl_len     real,          -- shoelace length     sl_unit    text           -- length unit );  create table unit (     un_name    text,          -- primary key     un_fact    real           -- factor transform cm );  create view shoelace     select s.sl_name,            s.sl_avail,            s.sl_color,            s.sl_len,            s.sl_unit,            s.sl_len * u.un_fact sl_len_cm       shoelace_data s, unit u      s.sl_unit = u.un_name;  create rule shoelace_upd on update shoelace     instead     update shoelace_data        set sl_name = new.sl_name,            sl_avail = new.sl_avail,            sl_color = new.sl_color,            sl_len = new.sl_len,            sl_unit = new.sl_unit      sl_name = old.sl_name; 

2) code have create rule :- failed , have same error get

not working

create rule shoelace_upd on update shoelace     instead     update shoelace_data        set shoelace_data.sl_name = new.shoelace_data.sl_name,            shoelace_data.sl_avail = new.shoelace_data.sl_avail,            shoelace_data.sl_color = new.shoelace_data.sl_color,            shoelace_data.sl_len = new.shoelace_data.sl_len,            shoelace_data.sl_unit = new.shoelace_data.sl_unit      shoelace_data.sl_name = old.shoelace_data.sl_name; 

edit:- getting error:-

error: column new.name not exist

because view not have 'name' field, view have these 3 fields :- product_name, price , category use these fields only

create rule prod_cat_upd on update products_with_categories  instead  update product         set name=new.product_name name=old.product_name