Need hint with MySQL query from 2 Tables - php

Question

I need a small hint... I've got 2 Tables.
Table 1 gets data from an external api.
Table 2 is static.
Table 1: data
id name status ratio import_id
1 Test online 3 1
2 Tee online 2 1
3 Test online 1 2
4 Tee online 0.01 2
5 Test offline 4 3
6 Teee online 3 3
7 Teet online 1 3
Table 2: names
id name tag active
1 Test t1 1
2 Tee t2 1
3 Teee t3 0
4 Teet t4 1
I want to have the ID from the table names (to write into another table and execute a cronjob)
Explanation Table 1:
id - AI
name - just the name
status - if the entry is active
ratio - the main select
import_id - every 10 minutes I do import from json (~40 entries)
what i've got:
$result = mysql_query("
SELECT
import_id
FROM
data
ORDER BY id DESC LIMIT 1");
while($raw = mysql_fetch_object($result))
{
$the_id = $raw->import_id;
echo $the_id;
}
Now I've got the ID and try to get the latest entry (import_id) with the highest ratio:
$c_result = mysql_query("
SELECT
name, active, ratio, import_id
FROM
data
WHERE
active = '1' AND import_id = '$the_id'
ORDER BY
ratio DESC LIMIT 1");
while($chosen = mysql_fetch_object($c_result))
{
$the_c = $chosen->name;
echo $the_c;
}
That works flawless.
But it is possible that one of the 40 entries provided by api is not in my table "names" or it is not marked as "active".
But I only want the names.id of
the name with the highest ratio
which is in my table "names"
which is marked as active in "names"
and the data.status is online
which is from the latest import (highest import_id)
and write it to another table.
I thought about a LEFT JOIN but if the names.name is not in the table "names" i just get an empty result.
Have you got a hint in the right direction?

Answer 1

SELECT d.name, active, ratio, import_id
FROM data d
JOIN names n ON d.name = n.name
WHERE import_id = (SELECT import_id
FROM data
ORDER BY id DESC
LIMIT 1)
AND d.status = 'online'
AND n.active = 1
ORDER BY ratio DESC
LIMIT 1
DEMO