php - MySQL: Unknown column 'price_USD' in 'field list' - Update operation - correct query (it runs on phpMyAdmin)

On an update query under Codeigniter framework, I got this error:

Query error: Unknown column 'price_USD' in 'field list' - Invalid query: UPDATEoffers_prices_history SETprice = '37',price_per_unit_of_active_ingredient = 0.061666666666667,unit_of_measure = 'GBP / mg',currencies_id = '23',price_USD = 46.93339,price_per_unit_of_active_ingredient_USD = 0.078222316666667,last_modified = '2019-06-11 18:44:38' WHEREid = '21'

If I copy and paste the entire query in phpmyadmin and run it, it works properly.

Here the DUMP of the used table:

    CREATE TABLE `offers_prices_history` (
      `id` int(11) UNSIGNED NOT NULL,
      `offers_id` int(11) UNSIGNED NOT NULL,
      `price` float NOT NULL,
      `price_per_unit_of_active_ingredient` float UNSIGNED NOT NULL,
      `price_USD` float DEFAULT NULL,
      `price_per_unit_of_active_ingredient_USD` float DEFAULT NULL,
      `unit_of_measure` varchar(255) NOT NULL,
      `currencies_id` int(11) UNSIGNED NOT NULL,
      `creation` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
      `last_modified` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8;

    --
    -- Dump dei dati per la tabella `offers_prices_history`
    --

    INSERT INTO `offers_prices_history` (`id`, `offers_id`, `price`, `price_per_unit_of_active_ingredient`, `price_USD`, `price_per_unit_of_active_ingredient_USD`, `unit_of_measure`, `currencies_id`, `creation`, `last_modified`) VALUES
    (6, 16, 25, 0.0416667, NULL, NULL, 'GBP / mg', 23, '2019-06-11 11:26:15', '2019-06-11 11:26:15'),
    (7, 16, 26, 0.0433333, NULL, NULL, 'GBP / mg', 23, '2019-06-11 11:28:03', '2019-06-11 11:28:03'),
    (8, 16, 27, 0.045, NULL, NULL, 'GBP / mg', 23, '2019-06-11 11:28:46', '2019-06-11 11:28:46'),
    (9, 16, 28, 0.0466667, NULL, NULL, 'GBP / mg', 23, '2019-06-11 11:37:58', '2019-06-11 11:37:58'),
    (10, 16, 29, 0.0483333, NULL, NULL, 'GBP / mg', 23, '2019-06-11 11:45:53', '2019-06-11 11:45:53'),
    (11, 16, 30, 0.05, NULL, NULL, 'GBP / mg', 23, '2019-06-11 11:52:10', '2019-06-11 11:52:10'),
    (12, 16, 31, 0.0516667, NULL, NULL, 'GBP / mg', 23, '2019-06-11 11:53:16', '2019-06-11 11:53:16'),
    (13, 16, 32, 0.0533333, 40.591, 0.0676517, 'GBP / mg', 23, '2019-06-11 15:42:19', '2019-06-11 15:42:19'),
    (14, 16, 32, 0.0533333, 40.591, 0.0676517, 'GBP / mg', 23, '2019-06-11 15:44:17', '2019-06-11 15:44:17'),
    (15, 16, 32, 0.0533333, 40.591, 0.0676517, 'GBP / mg', 23, '2019-06-11 15:45:12', '2019-06-11 15:45:12'),
    (16, 16, 33, 0.055, 41.8595, 0.0697659, 'GBP / mg', 23, '2019-06-11 15:56:07', '2019-06-11 15:56:07'),
    (17, 16, 34, 0.0566667, 43.128, 0.07188, 'GBP / mg', 23, '2019-06-11 16:33:30', '2019-06-11 16:33:30'),
    (18, 16, 33, 0.055, 41.8595, 0.0697659, 'GBP / mg', 23, '2019-06-11 17:30:50', '2019-06-11 17:30:50'),
    (19, 16, 33, 0.055, 41.8595, 0.0697659, 'GBP / mg', 23, '2019-06-11 17:54:22', '2019-06-11 17:54:22'),
    (20, 16, 35, 0.0583333, 44.3965, 0.0739941, 'GBP / mg', 23, '2019-06-11 18:15:37', '2019-06-11 18:28:04'),
    (21, 16, 36, 0.06, 45.6649, 0.0761082, 'GBP / mg', 23, '2019-06-11 18:33:47', '2019-06-11 18:33:47');

    --
    -- Indici per le tabelle scaricate
    --

    --
    -- Indici per le tabelle `offers_prices_history`
    --
    ALTER TABLE `offers_prices_history`
      ADD PRIMARY KEY (`id`),
      ADD KEY `ref_currency_id_idx` (`currencies_id`),
      ADD KEY `offers_prices_history_to_vendors_offers_idx` (`offers_id`);

    --
    -- AUTO_INCREMENT per le tabelle scaricate
    --

    --
    -- AUTO_INCREMENT per la tabella `offers_prices_history`
    --
    ALTER TABLE `offers_prices_history`
      MODIFY `id` int(11) UNSIGNED NOT NULL AUTO_INCREMENT, AUTO_INCREMENT=22;

    --
    -- Limiti per le tabelle scaricate
    --

    --
    -- Limiti per la tabella `offers_prices_history`
    --
    ALTER TABLE `offers_prices_history`
      ADD CONSTRAINT `offers_prices_history_to_vendors_offers_idx` FOREIGN KEY (`offers_id`) REFERENCES `phar263d_PharmaComparisonDB`.`vendors_offers` (`id`);
    COMMIT;

    /*!40101 SET [email protected]_CHARACTER_SET_CLIENT */;
    /*!40101 SET [email protected]_CHARACTER_SET_RESULTS */;
    /*!40101 SET [email protected]_COLLATION_CONNECTION */;
Copy code

The function that performs the update simply use an associative array

function update($id, $data)
{
    $this->db->where('id', $id);
    $this->db->update($this->table_name, $data);
}
Copy code

and the array is populated as stated in the error message. I cannot understand what attempt to do since the error shows a correct query, the column that gives an error is existing. I searched for similar posts, read a lot with the same title, but not found similar trouble that I can summarize in this way

• update operation
• not existing column error for an existing column
• column names correctly quoted in the query string
• the query shown in the error message runs correctly when copied and pasted in phpMyAdmin