Mysql Complex Where Clause

Question

I really surprised when I tried below code in MySQL:

SELECT * FROM table WHERE (key='free_shipping' and value='yes') AND (key='price' and value='5')

It doesn't work. I need to get product that is both free_shipping is 'yes' AND price equal '5' at the same time. How can I create this query properly?

Table Structure:

contents: (TABLE 1)

CONTENT_ID   TITLE  DESCRIPTION  DATE

content_fields: (TABLE 2)

FIELD_ID   CONTENT_ID    KEY_NAME    VALUE

Example (Get product that has 1 ID and its shipping is FREE):

SELECT *  FROM `contents` as c LEFT JOIN `content_fields` as cf ON  c.content_id = cf.content_id WHERE c.content_id = 1 AND  cf.key_name = 'free_shipping' AND cf.value = 'yes'

Answer 1

The brackets don't change the meaning of this statement. Without them you have:

key='free_shipping' and value='yes' and key='price' and value='5'
=>
key='free_shipping' and key='price'
=>
nothing!

try WHERE free_shipping='yes' AND price='5'

edit: scrap that, I'm now completely confused by your table. Is it just a load of key/value pairs? Could we see the table structure?

Answer 2

Try this:

WHERE free_shipping='yes' AND price='5'

or:

WHERE free_shipping=yes AND price=5

if the fields aren't strings

Answer 3

Your current query is contradictory as a single row can never match the WHERE clause. I assume you want something like this.

SELECT product_id
FROM table 
WHERE (key='free_shipping' and value='yes') or (key='price' and value='5')
GROUP BY product_id
HAVING COUNT(DISTINCT key) = 2

Answer 4

To get product titles that have free shipping and worth 5....... select distinct x.TITLE from contents x, content_fields y, content_fields z where x.CONTENT_ID = y.CONTENT_ID and y.CONTENT_ID = z.CONTENT_ID and y.key_name = 'free_shipping' and y.value='yes' and z.key_name = 'price' and z.value='5'