如何查询2个表和多个列？

Question

I researched this a bit already and all my attempts have come up short so far. I am trying to perform a mysql query in my php script that deals with multiple tables.

Here is what the tables look like:

TABLE 1

name

TABLE 2

Product (name)

Inventory

CatID

ProductID

TABLE 3

product_url

"name" (Table 1) must be the sane as "Product" (Table 2). Next, "Inventory" (table 2) must be = to "Y". Lastly, "CatID" must be = "2".

My attempt looked somewhat like this:

SELECT 1.name, 2.Product, 2.Inventory, 2.CatID
FROM table1 1, table2 2 
WHERE 2.Inventory = 'Y'
  AND 1.name = 2.Product
  AND 2.CatID = '2'

From the results, I would be looking to get more information from the table such as product description, etc which would be in table1 and table2... I have never joined or queried 2 (or more) tables before. Any help would be greatly appreciated.

Answer 1

Try this:

SELECT table1.Name, table2.Product, tabl2.Inventory, table2.CatID
FROM table1 INNER JOIN table2
ON table1.Name = table2.Product 
WHERE table2.CatID = '2'

Answer 2

SELECT t1.name, t2.Product, t2.Inventory, t2.CatID, t2.ProductID
FROM table1 t1
INNER JOIN table2 t2 ON t2.Product = t1.name
WHERE t2.Inventory = 'Y' AND t2.CatID = 2

I'm sorry to say that the database you have to work with was very poorly designed. If the query I gave you doesn't work, then make sure you have data in the tables that actually meets the criteria you're looking for.

Also remember that when you're accessing these fields in PHP, capitalization matters. You need to do something like this:

<?php

$q = QUERY FROM ABOVE
$r = mysql_query($q);
while($row = mysql_fetch_assoc($r)) {
    $name = $row["name"];
    $product = $row["Product"];
    $inventory = $row["Inventory"];
    $catid = $row["CatID"];
    $productid = $row["ProductID"];
}

?>