Question

I am having difficulty to explain this problem, but I will try anyway.

I have two different database rows

  SOMETHING
*---------------------------------------------------------*
|    id    |    category_id    |    body                  |
*---------------------------------------------------------*

  CATEGORY
*---------------------------------------------------------*
|    id    |    title    |    description                 |
*---------------------------------------------------------*

Now, I want to extract data from both rows at the samt time, how do i do this?

I need to extract values from SOMETHING and display the info from CATEGORY from the category_id in SOMETHING – how is this done the best way ?

I use to extract values like this:

$query = mysql_query("select * from SOMETHING WHERE id='$id' LIMIT 1");

while ($row = mysql_fetch_array($query)) {
   extract($row);

}

Answer 1

Use a join

SELECT
    S.id,
    S.category_id,
    S.body,
    C.title,
    C.description
FROM SOMETHING AS S
JOIN CATEGORY AS C
ON S.category_id = C.id
WHERE id = '42'
LIMIT 1

If there might not be a matching row in the CATEGORY table you could use a LEFT JOIN instead.