Question

尝试使用nodejs构建restapi我收到此错误

TypeError: Cannot call method 'getCategories' of undefined

我的项目结构是这样的

模型

- dbhandler.js

node_modules

的package.json

app.js

dbconnection.js

我的dbhandler代码在这里

var db = require('../dbconnection');
var getData = {
getCategories : function() {
    var sql = "SELECT * FROM categories"
    db.connection.connect();
    db.connection.query(sql,function(error, results, fields){
        if (!error){
            console.log('The solution is: ', results);
            console.log('The solution fields is: ', fields);
        } else{
            console.log('Error while performing Query.');
        }
    });
}};
module.exports = getData;

我的app.js代码在这里：

var dbhandler = require('./models/dbhandler')
var router = express.Router(); 
router.get('/', function(req, res) {
dbhandler.getData.getCategories();
res.json({ message: 'hooray! welcome to our api!' });   
});

Answer 1

当您通过此var dbhandler = require('./models/dbhandler')

将dbhandler作为对象导入时，它应该是dbhandler.getCategories（）

TypeError：无法调用undefined方法

1 个答案: