combine two queries as one without looping mysql - mysql

Question

how to join this in single query any help to combine these two queries as one without looping,
$today_date = mktime(0, 0, 0, $mon, $day-1, $year);
SELECT * FROM (`lead_follow_up`) LEFT JOIN `leads` ON `leads`.`id` = `lead_follow_up`.`lead_id` WHERE `date` <= $today_date GROUP BY `lead_follow_up`.`lead_id` ORDER BY `lead_follow_up`.`date` DESC
from the above query i get array $previou
$previou= Array
(
[0] => stdClass Object
(
[id] => 1
[lead_id] => 75943
[date] => 1438930800
[updated_on] => 1438884890
)
[1] => stdClass Object
(
[id] => 2
[lead_id] => 75943
[date] => 1416459600
[updated_on] => 1415901523
),
[2] => stdClass Object
(
[id] => 3
[lead_id] => 75943
[date] => 1416459600
[updated_on] => 1415901523
),....etc
);
foreach($previou as $key => $p):
$q = "SELECT `id` FROM (`lead_follow_up`) WHERE `lead_id` = '".$p->id."' AND `date` > '".$p->date."' ORDER BY `updated_on` DESC ";
if(!$this->db->query($q)){
$previouData[$key] = $p;
$pCount++;
}
endforeach;
how to join this in single query any help to combine these two queries as one without looping,

Answer 1

Your queries don't make much sense. For a start your first query has a GROUP BY lead_follow_up.lead_id but no aggregate functions. So in MySQL that will return one row for each value of lead_id (which row it returns is not defined).
Yet your array of sample data has multiple rows per lead_id so cannot have come from the query.
You are also LEFT OUTER JOINing the leads table, yet it doesn't seem to make sense to have a lead_follow_up which doesn't relate to a lead. As such you may as well use an INNER JOIN.
I am going to assume that what you want is a list of leads / lead_follow_ups and for each one a couple of all the follow ups after that particular follow up. That would give you something like this (making loads of assumptions as I do not know your table structure):-
SELECT leads.id AS lead_id,
lead_follow_up.id
lead_follow_up.`date`,
lead_follow_up.updated_on,
COUNT(lead_follow_up_future.id) AS future_lead_count
FROM leads
INNER JOIN lead_follow_up ON leads.id = lead_follow_up.lead_id
LEFT OUTER JOIN lead_follow_up AS lead_follow_up_future ON leads.id = lead_follow_up.lead_id AND lead_follow_up_future.`date` > lead_follow_up.`date`
WHERE lead_follow_up.`date` <= $today_date
GROUP BY leads.id AS lead_id,
lead_follow_up.id
lead_follow_up.`date`,
lead_follow_up.updated_on
ORDER BY lead_follow_up.date DESC