On 05/28/2017 10:53 AM, Michelle Konzack wrote:
On 2017-05-29 03:24:54 rob stone hacked into the keyboard:
You only need a single equals sign in SQL.
SELECT * FROM products WHERE category IN
(SELECT categories.cat FROM categories WHERE
categories.serial = products.category);
I have tried this too, but then I get:
ERROR: operator does not exist: integer = character varying
LINE 1: SELECT * FROM products WHERE category IN (SELECT categories....
^
My sql file is:
----8<------------------------------------------------------------------
DROP TABLE categories;
DROP TABLE manufacturers;
DROP TABLE products;
CREATE TABLE categories (
serial integer NOT NULL,
cat varchar(40),
);
CREATE TABLE manufacturers (
serial integer NOT NULL,
m_name varchar(40),
m_address varchar(200),
m_images varchar(100),
m_desc varchar(1000),
);
CREATE TABLE products (
serial integer NOT NULL,
category integer NOT NULL,
manufacturer integer NOT NULL,
p_name varchar(40),
p_images varchar(100),
p_desc varchar(10000),
);
----8<------------------------------------------------------------------
This is WHY I am puzzeling arround with the "integer" error.
Because you are comparing categories.cat which is a varchar to
products.category which is an integer. The above is crying out for
FOREIGN KEYS. For the time being I going to assume products.category is
a faux FK to categories.serial so;
SELECT * FROM products WHERE products.category = categories.serial;
--
Adrian Klaver
adrian.kla...@aklaver.com
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