query // how can i find _createdDate not working

Hello again,

First, we should be updating the row instead of inserting again, it has similar syntax:

 let toUpdate = { 
      "_id": id, 
      "newdateAsSt": formatdate 
};  
 
 wixData.update("myCollection", toUpdate) 
   .then( (results) => { let item = results; //see item below 
 }) 
   .catch( (err) => { let errorMsg = err; 
 }); 

Next, we need to figure out why the id is returning undefined. Try making it a global variable outside the .afterInsert() hook.

Best,
Majd