On Sun, May 28, 2017 at 10:33 PM, Michelle Konzack <linux4miche...@gmail.com > wrote:
> Hello *, > > I try to get columns from my database with a singel SELECT, but I stuck. > > I have 3 tables like: > > > 1) categories (serial,cat) > > 2) manufacturers (serial,m_name) > > 3) products (serial,category,manufacturer,p_name) > > > where the "category" and "manufacturer" > are numerical IDs from the two tables above. > > So I like to replace the numerical IDs with the appropriated values, > mean > > SELECT * FROM products WHERE category IN > (SELECT categories.cat FROM categories WHERE > categories.serial==products.category); > > But I get: > > ERROR: operator does not exist: integer==integer > LINE1: ...gories.cat FROM categories WHERE categories.serial==products. > category); > ^ > Hmm, "serial" is an "integer" and the "category" and "manufacturer" too. > > So whats wrong with it? > > > > > > > > -- > Michelle Konzack Miila ITSystems @ TDnet > GNU/Linux Developer 00372-54541400 > Wouldn't a simple join like the one below suffice: Select a.*,b.cat from products as a, categories as b where a.category=b.serial or am I missing something?
