Confused what this query is doing

[pouncer]

$result = mysql_query("select count(*) AS tot_people_per_rating,rating FROM item_rating WHERE item_id='$item_id' GROUP BY rating");

 

i don't understand it at all guys

[Psycho]

SELECT
    count(*) AS tot_people_per_rating,
    rating

This part of the query tell it to return two values. The first value is the number of records that are grouped together - more on this later. The 2nd value is from the rating field

 

FROM
    item_rating

This tells it what table to grab the data from

 

WHERE
    item_id='$item_id'

This instructs the query to only grab values for results where the item_id is a specific value

 

GROUP BY rating

This instructs the query to group records together where they have the same rating.

 

[MadTechie]

ahh Beat me too it (but explaind better!)

[pouncer]

so the count(*) thing, what does this actually count?

[MadTechie]

the found set

[Psycho]

Well, in this case it is counting the records in each grouped result. So, if there are 5 records in the table with the rating of 'B' your result set will include 1 record that represents those five records because of the GROUP BY clause. And the COUNT function wil create a value of 5. And the same process will create similar results for all other ratings in the table.