exports.save = function(req, res) {
connection.query('INSERT INTO student_details(name, course, units, grades, gwa) VALUES(?, ?, ?, ?, ?)',[req.body.name,req.body.course,req.body.units,req.body.grades,req.body.gwa], function(err, row) {
if(err) res.send('Error in query');
selectOne(row.insertId, function(newRow){
if(err) res.status(554).send('Error in query');
if(newRow == null){
res.send(552, {message: 'Student Details ('+row.insertId+') was not created.'});
} else{
res.status(200).send(newRow);
}
});
});
}
var selectOne = function(id, callback){
connection.query('SELECT * FROM student_details WHERE id=? LIMIT 1', [id], function(err, rows){
if(err) return err;
if(rows.length != 0){
callback(rows[0]);
}else{
callback(null);
}
});
}
我在执行上述查询时遇到错误。它说这个错误:
Uncaught TypeError: Cannot read property 'insertId' of undefined.
几个小时以来，我一直在努力解决这个问题，我的直觉是它与异步值有些相关，但我不知道如何解决它。
更新:
这是我的测试文件:
var studentdb = require(__dirname + '/../studentdb'),
student = require(__dirname + '/../student'),
index = require(__dirname + '/../index'),
should = require('should-http'),
assert = require('assert'),
request = require('supertest');
describe('Student Details', function() {
var url = 'http://localhost:1337';
var randomName = student.getRandomName(10);
var insertedId = 0;
describe('insert()', function () {
it('should create a new student record', function (done) {
var input = {
nameLength: 10,
subjectsLength: 5,
course: 'CAS'
};
studentName = student.getRandomName(input.nameLength);
studentCourse = student.getRandomCourse(input.course);
studentUnits = student.getRandomUnits(input.subjectsLength);
studentGrades = student.getRandomGrades(input.subjectsLength);
studentGWA = student.computeGWA(studentUnits, studentGrades,input.subjectsLength);
var stringUnits = studentUnits.join();
var stringGrades = studentGrades.join();
var generatedStudent = {
'name': studentName,
'course': studentCourse,
'units': stringUnits,
'grades': stringGrades,
'gwa': studentGWA
}
request(url)
.post('/addStudent')
.send(generatedStudent)
.end(function(err, res) {
if (err) {
throw err;
}
res.should.have.status(200);
res.body.should.have.keys(['id', 'name', 'course','units', 'grades', 'gwa']);
done();
});
});
});
describe('save()', function() {
console.log(insertedId);
it('should generate a student record', function(done) {
request(url)
.get('/generateStudent')
.end(function(err, res) {
if(err) throw err;
res.should.have.status(200);
res.body.should.not.have.property('name', null);
res.body.should.not.have.property('course', null);
generatedStudent = res.body;
done();
});
});
it('should not have duplicate name', function(done) {
request(url)
.get('/getStudents')
.end(function(err, res) {
if(err) throw err;
res.body.forEach(function(iteration) {
assert.notEqual(iteration, generatedStudent.name);
});
done();
});
});
it("now adding to the database", function(done) {
request(url)
.post('/addStudent')
.send(generatedStudent)
.end(function(err, res) {
if(err) throw err;
res.body.should.have.status(200);
console.log(res.body.id);
res.body.should.have.keys(['id', 'name', 'course', 'units', 'grades', 'gwa']);
done();
});
});
});
});
------------遵循 Zeeshan 的代码后的第二次更新---------------- 他们一直在评论部分拒绝我的修改。
同样，我已经尝试了你的建议，但仍然没有雪茄。我还打印了“newRow”以表明正在正确检索数据，只是当我尝试 res.send 函数时，它被读取为未定义，因此导致错误。感谢您的耐心等待!
Server Connected on port: 1337
Student Details
insert()
Database is connected ... nn
If error, I should not be printed
Value of row.insertId 34
{ id: 34,
name: 'H3tno72Osk',
course: 'BS Computer Science',
units: '4,1,2,4,2',
grades: '3.0,3.0,3.0,3.0,4.0',
gwa: 3 }
✓ should create a new student record (66ms)
save()
✓ should generate a student record
✓ should not have duplicate name
1) now adding to the database
3 passing (90ms)
1 failing
1) Student Details save() now adding to the database:
Uncaught AssertionError: expected Object { body: undefined, statusCode: undefined } to have property statusCode of 200 (got undefined)
at Assertion.fail (node_modules/should/lib/assertion.js:92:17)
at Assertion.Object.defineProperty.value [as status] (node_modules/should/lib/assertion.js:164:19)
at Test.<anonymous> (test/studentdb.js:86:27)
at Test.assert (node_modules/supertest/lib/test.js:156:6)
at assert (node_modules/supertest/lib/test.js:127:12)
at node_modules/supertest/lib/test.js:124:5
at Test.Request.callback (node_modules/supertest/node_modules/superagent/lib/node/index.js:691:12)
at IncomingMessage.<anonymous> (node_modules/supertest/node_modules/superagent/lib/node/index.js:922:12)
at _stream_readable.js:920:16
最佳答案
稍微修改一下，您也可以尝试一下并更新结果吗？
exports.save = function(req, res) {
connection.query('INSERT INTO student_details(name, course, units, grades, gwa) VALUES(?, ?, ?, ?, ?)',[req.body.name,req.body.course,req.body.units,req.body.grades,req.body.gwa], function(err, row) {
if(err) return res.send('Error in query');
console.log("If Errror I should not pe printed");
console.log("Value of row.insertId ", row.insertId);
selectOne(row.insertId, function(newRow, insertId){
if(err) res.status(554).send('Error in query');
if(newRow == null){
res.send(552, {message: 'Student Details ('+insertId+') was not created.'});
} else{
res.status(200).send(newRow);
}
});
});
}
var selectOne = function(id, callback){
connection.query('SELECT * FROM student_details WHERE id=? LIMIT 1', [id], function(err, rows){
if(err) return err;
if(rows.length != 0){
callback(rows[0], id);
}else{
callback(null, id);
}
});
}
关于javascript - 查询结果未定义，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/36371763/