javascript - 使用mysql通过javascript访问全局函数

Question

我试图在访问内容之前验证用户。我已经在全局声明了函数并将其传递到体内。当我运行它时，出现错误:用户不存在。请让我知道我哪里出错了。

function validate(user_id){ 
var user_id = db.query('select user_id from user WHERE user_id = ?', [user_id], 
function(error,rows) {
if (user_id != user_id) {
  return false;
} else {
  return true;
}
}); 
}

router.post('/addcustomerskills', function(req,res) {
if (validate(user_id == true)) {
  return true;
     // my code should execute
}else {
    response.success= false;
    response.mssg = "User Doesn't Exist";
    res.json(response);
}

Answer 1

function validate(user_id, req, res){
    db.query('select user_id from user WHERE user_id = ?', [user_id], function(error,rows) {
        if (error || rows.length === 0) {
            var response = {}
            response.success= false;
            response.mssg = "User Doesn't Exist";
            res.json(response);
        } else {
            // my code should execute
            return true;
        }
    });
}

router.post('/addcustomerskills', function(req,res) {
    validate(req.body.user_id, req, res);
})