nozzy

if($_SERVER['REQUEST_METHOD'] == 'POST' && isset($_POST['age'])){

function delete_litres_book($hub_id){
    global $mysqli;
    //удаляем книги путем простановки options=0
    $q = "UPDATE `litres_data` SET options=0 WHERE hub_id=" . $hub_id;
    $mysqli->query($q);
  }

select,
t1.title, 
t2.category,
count(*)
from main_menu t1
join products t2 on t2.category = t1.id
where t1.title = '...'
group by t1.title, t2.category

SELECT master_id, COUNT(*) FROM master_user WHERE city_id = 4019 GROUP BY master_id

select
t2.`name`,
t3.`name`
from a t1
join b t2 on t2.id = t1.id1
join b t3 on t3.id = t1.id2

select
t1.*,
t2.*,
t3.*
from
avto t1
left join light t2 on t2.avto_id = t1.id and t1.choice = 0
left join bamper t3 on t3.avto_id = t1.id and t1.choice = 1

SELECT region.region_name, COUNT(gorod.city_name) 
FROM region INNER JOIN gorod 
ON region.region_id = gorod.region_id
GROUP BY region.region_name;

select
t1.*,
t2.*
from table1 t1
join table2 t2 on t2.first_id = t1.id
where t2.second_id = 111

select
t1.*,
t2.*,
t3.*
from
TABLE_PRODUCTS_TO_PRODUCTS_EXTRA_FIELDS t1
join TABLE_PRODUCTS t2 on t2.products_id = t1.products_id
join TABLE_PRODUCTS_DESCRIPTION t3 on t3.products_id = t1.products_id
where t1.products_extra_fields_id = '4'
and t1.products_extra_fields_value = 'Y'
limit 5