API endpoint.txt

const express = require('express');
const bodyParser = require('body-parser');
const DuckDB = require('duckdb');

const app = express();
const db = new DuckDB();

// parse application/json
app.use(bodyParser.json());

// endpoint to execute dynamic SQL query based on input criteria
app.post('/segment', async (req, res) => {
  try {
    const { criteria } = req.body;

    // build dynamic SQL query based on input criteria
    let sql = 'SELECT * FROM users';
    let whereClause = '';

    for (const key in criteria) {
      if (criteria.hasOwnProperty(key)) {
        if (whereClause === '') {
          whereClause += ` WHERE ${key} = '${criteria[key]}'`;
        } else {
          whereClause += ` AND ${key} = '${criteria[key]}'`;
        }
      }
    }

    if (whereClause !== '') {
      sql += whereClause;
    }

    // execute SQL query
    const result = await db.query(sql);

    // return result as JSON
    res.json(result);
  } catch (err) {
    console.error(err);
    res.status(500).send('Error executing query');
  }
});

app.listen(3000, () => {
  console.log('Server listening on port 3000');
});