Complicated loop of queries into a single one - mysql

Question

I need a little bit of help with making a complicated query, i will try to explain what i am trying to accomplish down below.
Here is my data
table_one
+---------+---------+----------+----------+
| user_id | poly_id | in | out |
+---------+---------+----------+----------+
| 900 | 1 | 20-12-17 | 20-12-17 |
| 900 | 2 | 21-12-17 | 22-12-17 |
| 900 | 3 | 22-12-17 | 24-12-17 |
| 900 | 1 | 23-12-17 | 26-12-17 |
| 444 | 4 | 24-12-17 | 28-12-17 |
| 444 | 4 | 25-12-17 | 30-12-17 |
| 444 | 5 | 26-12-17 | 01-01-18 |
| 444 | 3 | 27-12-17 | 03-01-18 |
| 900 | 2 | 28-12-17 | 05-01-18 |
| 900 | 1 | 29-12-17 | 07-01-18 |
| 444 | 2 | 30-12-17 | 09-01-18 |
+---------+---------+----------+----------+
table_two
+----+---------+-------------+---------+
| id | name | type | product |
+----+---------+-------------+---------+
| 1 | city 1 | gas station | general |
| 2 | city 2 | workshop | general |
| 3 | city 3 | paint | bikes |
| 4 | city 4 | paint | general |
| 5 | city 5 | gas station | cars |
| 6 | city 6 | gas station | bikes |
| 7 | city 7 | paint | cars |
| 8 | city 8 | workshop | cars |
| 9 | city 9 | gas station | general |
| 10 | city 10 | gas station | cars |
| 11 | city 11 | gas station | general |
+----+---------+-------------+---------+
i have a working solution that looks like this
//results comes from somewhere else, it looks something like this for example:
array (
"user_id" => "poly_id of the last gas station"
"900" => 1,
"444" => 10
)
foreach ($result AS $res ) {
$query = "
SELECT
table_one.name AS name
FROM
`table_one`
LEFT JOIN
`table_two` ON table_one.poly_id = table_two.id
WHERE
`table_two`.type = 'gas station '
AND
table_one.user_id = $res['user_id']
AND
table_one.poly_id != $res['poly_id']
AND
table_one.in >= "some date from'
AND
table_one.out <= 'some date to'
AND
(FIND_IN_SET('general', table_two.product) > 0 OR FIND_IN_SET('cars', table_two.product) > 0 )
ORDER BY out DESC LIMIT 1
";
//if the results is not empty use the result['name']
}
The idea is: I have the user last gas station, but i need to find the previous one between a date range.
As i said, the above example is working just fine, however i need to be able to process multiple results at once, and sometimes the results are ~2000.
Which means 2000+ queries per request.
Is it even possible to somehow optimize this loop of queries into a single one, so I don't do 2000 queries per request ?
If possible, how :D
Thanks.

Answer 1

This query will return result contains user_id with it's last
enter in the given periode.
one thing here because you are
using date not date time if the user exit in the same
day two time you will have two record of that user you can skip the second
record in you code
select
user_id,
in,
out
from table_one t1
INNER JOIN (
select
user_id
max(out) as 'max_out',
from
table_one
where
in >= ? AND
out <= ? AND
ploy_id not in [list_of_unwanted_ploy_id]
-- you can specify any condition here
group by user_id
) l_out on t1.user_id = l_out.user_id and t1.out = l_out.max_out
where
t1.user_id in [list_of_user_id]