title: ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
body: <p>this is my routes code in express. 
  when i try to delete or post in postman, appear this error in console </p>
  
  <pre><code>Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
      at ServerResponse.setHeader (_http_outgoing.js:485:11)
      at ServerResponse.header (/Users/ivanolvera/Movvel/Server/node_modules/express/lib/response.js:771:10)
      at ServerResponse.send (/Users/ivanolvera/Movvel/Server/node_modules/express/lib/response.js:170:12)
      at Query.&lt;anonymous&gt; (/Users/ivanolvera/Movvel/Server/src/routes/modelo.js:56:9)
      at Query.&lt;anonymous&gt; (/Users/ivanolvera/Movvel/Server/node_modules/mysql/lib/Connection.js:526:10)
      at Query._callback (/Users/ivanolvera/Movvel/Server/node_modules/mysql/lib/Connection.js:488:16)
      at Query.Sequence.end (/Users/ivanolvera/Movvel/Server/node_modules/mysql/lib/protocol/sequences/Sequence.js:83:24)
      at Query.ErrorPacket (/Users/ivanolvera/Movvel/Server/node_modules/mysql/lib/protocol/sequences/Query.js:92:8)
      at Protocol._parsePacket (/Users/ivanolvera/Movvel/Server/node_modules/mysql/lib/protocol/Protocol.js:291:23)
      at Parser._parsePacket (/Users/ivanolvera/Movvel/Server/node_modules/mysql/lib/protocol/Parser.js:433:10) {
    code: 'ERR_HTTP_HEADERS_SENT'
  }
  </code></pre>
  
  <pre><code>    // delete by id 
  
      router.delete("/:idModelo", function(req, res, next) {
        const id = req.params.idModelo;
        const sql = `DELETE * FROM Modelo WHERE idModelo=${id}`;
        pool.query(sql, function(err, row, fields) {
          if (err) {
            res.status(500).send({ error: "Something failed!" });
          }
          res.send("Deleted");
        });
      });
  </code></pre>