Use MySQL result in another query

Question

I have this code which lists everything in tbl_inventory for a given company which works fine:

$result_inventory = mysqli_query($con,"SELECT * FROM tbl_inventory WHERE company_id='$company_id' ORDER BY ip_address")

while($row = mysqli_fetch_array($result_inventory))
echo "<td>{$row['type']} </td>";
echo "<td>{$row['ip_address']} </td>";
echo "<td>{$row['site']} </td>";

The site column gives a number which correlates to an ID in another table which I want to use to run another query such as:

SELECT name FROM tbl_sites WHERE site_id='$site'

However I'm not sure on how to define $site from the previous result

Could someone point me in the right direction?

Answer 1

You could use something like:

$result_inventory = mysqli_query($con,"SELECT * FROM tbl_inventory WHERE company_id='$company_id' ORDER BY ip_address")

while($row = mysqli_fetch_array($result_inventory)){
  echo "<td>{$row['type']} </td>";
  echo "<td>{$row['ip_address']} </td>";
  $result2 = mysqli_query($con,"SELECT name FROM tbl_sites WHERE site_id='$row[site]'")
  if ($row2 = mysqli_fetch_array($result2))
    echo "<td>{$row2['name']} </td>";
}

but i think it's a so inefficient

Answer 2

@Rayblade's answer seems legit, however, you can also perform a JOIN -statement between the two tables:

SELECT tbl_sites.name FROM tbl_inventory 
LEFT JOIN tbl_sites ON tbl_inventory.site = tbl_sites.site_id 
WHERE tbl_inventory.company_id='$company_id' 
ORDER BY tbl_inventory.ip_address

This will successfully get the tbl_sites.name column, for every company that matches a site. Here you can of course get any arbitrary number of columns, just make sure to use the table name as prefix, since we now have two tables in the query.