holllop

function createValuesTemplate(length) {
  const numColumns = 9; 
  const placeholders = [];
  let placeholderIndex = 1; 

  for (let i = 0; i < length; i++) {
    let rowPlaceholders = [];
    for (let j = 0; j < numColumns; j++) {
      rowPlaceholders.push('$' + placeholderIndex++);
    }
    placeholders.push('(' + rowPlaceholders.join(', ') + ')');
  }

  return placeholders.join(', ');
}

async function accepting_expenses_array(req, res) {
  const expenses_array = req.body;
  const expenses_as_numbers = expenses_array.map(Number);
  console.log("expenses_as_numbers",expenses_as_numbers)
  try {
    // Первое число - id_order. Ищем максимальный id_work
    const results = await pool.query('SELECT id_work FROM "works" WHERE id_order = $1', [expenses_as_numbers[0]]);
    
    const work_id_array = results.rows.map(row => row.id_work);
    const work_id_max = Math.max(...work_id_array);
    console.log("work_id_max",work_id_max)

    const expensesWithoutFirst = expenses_as_numbers.slice(1); // Игнорируем первый элемент, id_order

    const newExpensesArray = [];
    for (let i = 0; i < expensesWithoutFirst.length; i += 8) {
      // Добавляем work_id_max в начало каждой строки значений
      newExpensesArray.push(work_id_max, ...expensesWithoutFirst.slice(i, i + 8));
    }
    console.log("newExpensesArray",newExpensesArray)
    if (newExpensesArray.length % 9 !== 0) {
      return res.status(400).json({
        success: false,
        error: 'Количество элементов в массиве расходов должно быть кратным числу столбцов таблицы (включая work_id_max).'
      });
    }
    
    // Подготовка SQL запроса на вставку
    const insertQuery = `INSERT INTO "expenses" (
      n_plan, 
      type_work_id, 
      printer_id, 
      material_id,
      format_id, 
      performer_id, 
      n_sheets, 
      n_page, 
      n_ruined
    ) VALUES ${createValuesTemplate(newExpensesArray.length / 9)};;`

    console.log("createValuesTemplate(newExpensesArray.length / 9)",createValuesTemplate(newExpensesArray.length / 9))

    // Выполняем запрос на вставку с newExpensesArray
    const insertResult = await pool.query(insertQuery, newExpensesArray);
    console.log("insertResult",insertResult);
    // Отправляем успешный ответ
    return res.json({ success: true, message: 'Данные успешно добавлены.' });
  } catch (error) {
    // Логирование ошибки и отправка ошибочного ответа
    console.error('Error during query execution:', error.stack);
    return res.status(500).json({
      success: false,
      error: error.message
    });
  }
}

TypeError: Converting circular structure to JSON
    --> starting at object with constructor 'Socket'
    |     property 'parser' -> object with constructor 'HTTPParser'
    --- property 'socket' closes the circle

function loadSelectOptions2(url, selectElement) {
  fetch(url)
    .then(response => response.json())
    .then(data => {
      data.forEach(item => {
        const option = createOption(item.printer_id, item.material);
        selectElement.appendChild(option);
      });
    })
    .catch(error => {
      console.error(error);
      // Обработать ошибку
    });
}
selectElement2.addEventListener('change', () => {
    const selectedPrinterId = selectElement2.value;
    console.log('selectedPrinterId:', selectedPrinterId);
    // Очистить select3 перед загрузкой новых опций
    selectElement3.innerHTML = '';
    // Загрузить опции для select3 на основе выбранного значения select2
    if (selectedPrinterId) {
      const url = `http://:3000/printer_material?printer_id=${encodeURIComponent(selectedPrinterId)}`;
      loadSelectOptions2(url, selectElement3);
    }
  });

const http = require('http');
const express = require('express');
const bodyParser = require('body-parser');
const cors = require('cors');
const db = require('./pool');

const app = express();
const port = 3000;

app.use(bodyParser.json());
app.use(
  bodyParser.urlencoded({
    extended: true,
  })
);
app.use(cors());
app.get('/printer_material', (req, res) => {
  const printer_id = parseInt(req.query.printer_id, 10);

  console.log('Received printer_id:', printer_id); // Вывод значения в консоль как число

  db.getPrinter_material(printer_id, res);
});
http.createServer(app).listen(port, () => {
  console.log(`App running on port ${port}.`);
});

//pool.js
const { response } = require('express');

const Pool = require('pg').Pool;
const pool = new Pool({
  user: '',
  host: '',
  database: '',
  password: '',
  port: 5432,
});

const getPrinter_material = (printer_id, response) => {
  console.log('Received printer_id:', printer_id); 

  pool.connect((error, client, release) => {
    if (error) {
      throw error;
    }

    const query = {
      text: `SELECT pr.printer_id, m.material FROM printer_material pm JOIN printer pr ON pm.printer_id = pr.printer_id JOIN material m ON pm.material_id = m.material_id WHERE pr.printer_id = $1`,
      values: [printer_id],
    };

    console.log('Query text:', query.text);

    client.query(query, (error, results) => {
      release();

      if (error) {
        throw error;
      }

      console.log(results.rows);
      response.json(results.rows);
    });
  });
};
module.exports = {
  getPrinter_material,
};