javascript - Express - 循环查询时 Promise 挂起

Question

我收到一个包含多个数据的数组，我必须对数组的每个元素进行查询。但这是给我一个未决的 promise 。我该如何解决这个问题？有什么问题吗？

       getFamilies(req, res)
      {
        console.log(req.params.data);
        var parsedData = JSON.parse(req.params.data);
        var compounds = parsedData[0].compounds;
        var supplier = parsedData[0].supplier;
        var families = parsedData[0].families;
        console.log(parsedData[0].compounds.length);

        var parts = [];
        for (var i = 0; i < compounds.length; i++)
        {
          console.log(families[i]);
          console.log("SELECT u_part.u_idpart, u_part.u_order, u_part.u_familia, st.fornecedor, st.design, st.ref FROM u_part INNER JOIN st ON u_part.u_familia = st.familia WHERE st.fornecedor ='" + supplier +"' and u_part.u_familia="+ families[i]);
          parts.push(request.query("SELECT u_part.u_idpart, u_part.u_order, u_part.u_familia, st.fornecedor, st.design, st.ref FROM u_part INNER JOIN st ON u_part.u_familia = st.familia WHERE st.fornecedor ='" + supplier +"' and u_part.u_familia="+ families[i]));
        }

        return Promise.all([parts]).then(function(listOfResults)
        {
            console.log(listOfResults[0]);
          console.log("done");
        }).catch(function(err)
        {
            // ... query error checks
            console.log(err);
        });
}

谢谢

Answer 1

Promise.all 接受一个 Promise 数组，其中 parts 已经是，而不是一个 Promise 数组的数组 ([parts]) 。使用

return Promise.all( parts ).then…
//                 ^     ^