Adding, editing, reading data on google spreadsheets

[Taylan_Safak_YAZICI]

Hello guys,

I have a problem about reading data from google sheet. There are so many topics about this but i just didn't get it. And i don't have any knowledge about app script thing. So i need a little help here. I will share some screenshots below.

Next screenshot shows the responsecontent.

And this is the error that i get,

I don't know whether there is no connection between sheet and the app or the web app doesn't work. And if the script is wrong, i'm going to need help about editing part too. What im trying to do is, edit the data that i choose on listview, to do that i need to read the data first.
Any help appreciated,
Thank you all.

[TIMAI2]

Is your web app "bound" to the spreadsheet or a standalone web app ? (Did you create the script project from within the spreadsheet ?)

[TIMAI2]

It looks like you have followed a youtube video by Hay Kel, who copied my blocks and script, but then changed things and his example is incorrect.

If the web app is bound to the spradsheet:

Try changing:

var sh = ss.getSheets()[0];
to
var sh = ss.getSheetByName('Sheet1');

and don't forget to update your web app to a new version after changes.

[TIMAI2]

Here an updated version of my original work:

Google Sheet CRUDQ II

[Taylan_Safak_YAZICI]

This is a cool work, congrats! I just tried to create both sheet and the script from the beginning. And script was standalone before, now its bounded to sheet. Now it works,

I'm going to try to built the editing part now and i think that great work of yours will be so usefull for me. I will let you know when i'm struggling.
Thank you for your help.