app.get('/api/search', async (req, res) => {
  const { instanceId, packageType, os, instanceType, startDate, endDate } = req.query;
  console.log("here at receiving query: ", instanceId, packageType, os, instanceType, startDate, endDate);
  console.log(typeof(instanceId));
  try {
    const query = `
    SELECT * FROM packages_db
    WHERE
          ($1 IS NULL OR instance_id = $1) AND
          ($2 IS NULL OR package_modules = $2) AND
          ($3 IS NULL OR os_type_version = $3) AND
          ($4 IS NULL OR instance_type = $4) AND
          ($5 IS NULL OR creation_time BETWEEN $5 AND $6);`

    // Execute the SQL query with the provided parameters
    const result = await pool.query(query, [instanceId, packageType, os, instanceType, startDate, endDate]);

    // Return the result from the database
    res.json(result.rows);
  } catch (error) {...}

Error : Error executing query: error: could not determine data type of parameter $1

Tried to specify the datatype that didn’t work.

const query = `
    SELECT * FROM packages_db
    WHERE
          ($1 IS NULL OR instance_Id = ($1::text)::integer) AND
          ($2 IS NULL OR package_modules = $2::text) AND
          ($3 IS NULL OR os_type_version = $3::text) AND
          ($4 IS NULL OR instance_type = $4::text) AND
          ($5 IS NULL OR creation_time BETWEEN $5::timestamp AND $6::timestamp);`

// Execute the SQL query with the provided parameters
const result = await pool.query(query, [instanceId, packageType, os, instanceType, startDate, endDate]);

Got this error instead:

Error executing query: error: syntax error at end of input