static addSale(products){

        //WHERE (SELECT stock FROM prais_informations WHERE code = ) > 20;
        let quer = 'INSERT INTO `sales` (`id`, `code`, `quantity`, `price`, `sum`, `idCheck`) VALUES ?;';            

        return new Promise((resolve, reject) => {
           
        pool.getConnection((err, connection) => {
            if (err)reject(err);
            
            connection.query(quer, [products.map(item => [null, item.id, item.quantity, item.price, item.sum, 3])], (err, rows) => {
                 if (err) {
                    reject(err);
                }

                resolve(rows);
                connection.release();
            });
        });
     });
    }

"INSERT INTO table (count) SELECT N WHERE (SELECT balance FROM table LIMIT 1) > N"

"INSERT INTO table (count) SELECT N WHERE (SELECT balance FROM table LIMIT 1) > N"

INSERT INTO `sales` (`id`, `code`, `quantity`, `price`, `sum`, `idCheck`) 
VALUES 
(null, item.id, item.quantity, item.price, item.sum, 3), 
(null, item.id, item.quantity, item.price, item.sum, 3)
, ... , 
(null, item.id, item.quantity, item.price, item.sum, 3);

SELECT true WHERE (SELECT prais_informations.stock FROM prais_informations WHERE prais_informations.code = 1 LIMIT 1) > 7 
UNION
 SELECT true WHERE (SELECT prais_informations.stock FROM prais_informations WHERE prais_informations.code = 2 LIMIT 1) > 3

SELECT prais_informations.stock <=  количество для товара 0*  FROM prais_informations WHERE prais_informations.code = код товара 0*
...
SELECT prais_informations.stock <= количество для товара n* FROM prais_informations WHERE prais_informations.code = код товара n*

var data = [
    [code, quantity, ....],
    [code, quantity, ....],
    ....
];

data.forEach((d)=> {
    query('INSERT INTO sales (code, quantity, ...) SELECT ' + d.join(',') + ' WHERE (SELECT stock FROM pi WHERE code=' + d.code + ') >=' + d.quantity)
})

'SELET 1 WHERE NOT EXISTS (SELECT * FROM pi WHERE code IN(sales.code, sales.code, ....) AND stock BETWEEN sales.quantity.min AND sales.quantity.max)'

UPDATE table_to_update 
SET  cod_user= CASE WHEN user_rol = 'student' THEN '622057'
                   WHEN user_rol = 'assistant' THEN '2913659'
                   WHEN user_rol = 'admin' THEN '6160230'
               END
    ,date = '12082014'
WHERE user_rol IN ('student','assistant','admin')
  AND cod_office = '17389551';

BEGIN

DECLARE res INT;
DECLARE last_index INT;
SET @input := 'sales:  [  { id: 2, quantity: 5, price: 123, sum: 615 },  { id: 1, quantity: 9, price: 97, sum: 873 } ]';

SET @input:=REPLACE(@input, ' ', '');
SET @input:=REPLACE(@input, 'sales:', '');
SET @input:=REGEXP_REPLACE(@input, '([{,])([a-z])', '$1"$2');
SET @input:=REGEXP_REPLACE(@input, '([a-z]):', '$1":');

CREATE TEMPORARY TABLE new_tbl SELECT jtin.id AS jtin_id, jtin.quantity AS jtin_qty, pi.stock AS pi_qty, pi.price AS pi_price
FROM JSON_TABLE(@input,
                "$[*]"
                COLUMNS (id INT PATH "$.id" ,
                         quantity MEDIUMINT PATH "$.quantity",
                         price DECIMAL(7,2) PATH "$.price",
                         `sum` DECIMAL(8,2) PATH "$.sum"
                         )) AS jtin 
                LEFT JOIN prais_informations AS pi ON jtin.id  = pi.code;

SET res = (SELECT count(*) FROM new_tbl WHERE jtin_qty > pi_qty);

IF res = 0 THEN 
/*
  Инсертим новую запись, получившийся id, будет являтся id чека
*/
INSERT INTO checks(`data`, `user`) VALUES ( UNIX_TIMESTAMP(), 0);
SET last_index = (SELECT max(id) FROM checks);
/*
  Инсертим содержимое массива заказа в таблицу регистрации
*/
INSERT INTO sales(`code`, `quantity`, `price`, `sum`, `idCheck`) SELECT nt.jtin_id, nt.jtin_qty, nt.pi_price, (nt.jtin_qty * nt.pi_price), last_index FROM new_tbl AS nt;

/*
  Обновляем остатки на складе
*/

END IF

END