在Node.js中的mysql查询中无法访问变量？
在Node.js中的mysql查询中无法访问变量？
提问于 2018-10-10 00:55:13
嗨我正在将一个bot框架的会话变量传递给这个函数，它工作正常但是当我尝试在conn.query（内部函数）中访问它时，它是无法访问的。这是代码片段
function hopitalSearch(city, treatment, context, callback) {
conn = mysql.createConnection(db_config);
conn.connect(
function (err) {
if (err) {
console.log("!!! Cannot connect !!! Error:");
throw err;
}
});
var hospitalList = [];
var basic_query = 'SELECT hospital_name FROM hospital_list WHERE hospital_location="' + city + '" AND treatment_name="' + treatment + '" LIMIT 10';
conn.query(basic_query, function (err, results, fields) {
if (err) throw err;
for (var i = 0; i < results.length; i++) {
hospitalList.push(JSON.stringify(results[i].hospital_name));
}
console.log(hospitalList);
console.log("showing context")
console.log(context); //not accessible
}); }
回答 1
Stack Overflow用户
发布于 2018-10-10 10:34:26
尝试使用async / await。
注意：不要忘记使用TRY / CATCH。
async function hopitalSearch(city, treatment, context, callback) {
conn = mysql.createConnection(db_config);
await conn.connect();
var hospitalList = [];
var basic_query = 'SELECT hospital_name FROM hospital_list WHERE hospital_location="' + city + '" AND treatment_name="' + treatment + '" LIMIT 10';
var results = await conn.query(basic_query);
for (var i = 0; i < results.length; i++) {
hospitalList.push(JSON.stringify(results[i].hospital_name));
}
console.log(hospitalList);
console.log("showing context")
console.log(context);
}
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原文链接：
https://stackoverflow.com/questions/-100002869
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