Javascript Express:forEach完成后呈现视图

我有一个在循环内部执行的更新查询

我想在forEach循环完成迭代时渲染视图

代码：

---

您可以使用索引：

resultData.forEach((element, index) => {
    /*...*/
});

然后添加此条件以发送响应：

if (index === resultData.length - 1) {
    res.render('updated.ejs')
}

完整代码：

conn.query(`SELECT Id, ${sfColumn} from Lead`, function (err, result) {
    if (err) { return console.error(err) }

    var resultData = result.records

    resultData.forEach((element, index) => {

        var sfColumnValue = null
        if (element[sfColumn] == null) {
            sfColumnValue = null
        } else {
            sfColumnValue = "'" + element[sfColumn] + "'"
        }

        var updateSql = `UPDATE leads SET ${localColumn} = ${sfColumnValue} WHERE sid = '${element.Id}'`

        dbConfig.varConnection[dbName].query(updateSql, function (err, data) {
            if (!err) {
                console.log("data", data)
                if (index === resultData.length - 1) {
                    res.render('updated.ejs')
                }
            }
            else
                console.log('Error while performing Query.', err);
        });
    })
});

---

使用resultData.length更新答案

conn.query(`SELECT Id, ${sfColumn} from Lead`, function (err, result) {
    if (err) { return console.error(err) }

    var resultData = result.records

    resultData.forEach((element, index) => {

        var sfColumnValue = null
        if (element[sfColumn] == null) {
            sfColumnValue = null
        } else {
            sfColumnValue = "'" + element[sfColumn] + "'"
        }

        var updateSql = `UPDATE leads SET ${localColumn} = ${sfColumnValue} WHERE sid = '${element.Id}'`

        dbConfig.varConnection[dbName].query(updateSql, function (err, data) {
            if (!err) {
                console.log("data", data)
                if (index === resultData.length - 1) {
                    res.render('updated.ejs')
                }
            }
            else
                console.log('Error while performing Query.', err);
        });
    })
});