keep getting this errror :" Cast to ObjectId failed for value" using mongodb with nodejs-CodePudding

I am new to coding and trying to build an APi using NOde js, express and mongodb

here is my code

router.get('/:id', async(req, res) => {  
console.log(req.params.id);
try{    
        const show = await Show.findById(req.params.id);
        const _iD = show._id.toHexString()
        console.log(_iD );
        if(req.params.id === _iD){
        res.json(show);      
        } else {
            res.send("not right ID");
        }
}

catch(err){
    console.log("error"   err)
}
})

it not working out,if "you enter a wrong ID intentionally " and should get " not right ID ", but it gets "Cast to Object ID failed for value".

CodePudding user response：

Try out this function

function isMongooseId(id) {
    var valid = false;
    try{
        if(id == mongoose.Types.ObjectId("" id)) valid = true;
    } catch(e){
        valid = false;
    }
    return valid;
}

// You can use it like this,

if(isMongooseId(req.params.id)) {
    // Perform your db operation
}

CodePudding user response：

Make sure the "intentionally wrong ID" still respect the objectId syntax (24 hexadecimal characters i would say). Otherwise you will fail at the Show.findById and jump right into the catch.

Then, i'm not sure of what your trying to do.

If you provide an ID that is not present in the collection, Show.findById will not return any object so you won't be able to get its ID with show._id.toHexString() and you will, again, jump to the catch.

And if the ID is in the collection, req.params.id === _iD will always be true and you will never reach the else.

Instead you should just check if show contain an object