select clause help needed

[mcshen]

i have 3 tables.

table category has 2 fileds. they are
id, category_name

table classify has 2 fields, they are
category_id, customer_id

table customer has 3 fileds, they are
id, address, phone

i need to query the db and find out what category.category_name is when classify.customer_id=5

i have tried it so many times. Help me out. Thx.

[barand]

$id = 5;
$sql = "select category.category_name from category "
. " inner join classify on category.id = classify.category_id "
. " inner join customer on classify.customer_id = customer.id "
. " where customer.id = $id ";

$query = mysql_query($sql);

while ($row = mysql_fetch_array($query)) {
    echo "$row['category_name']<br>";
}

Your structure permits a customer to belong to several categories, the above lists them all for the specified customer.

hth