在indexedDB事件处理程序中定义或更改的变量

Question

我正在使用indexedDB，但遇到了问题。问题是当我请求某些事务（例如添加或从数据库读取）时。当我处理事件[成功，onerror]并将变量的值/分配给变量时，它会保留该值，并且可以在该处理程序内访问，但在处理程序外该值不会更改。

let getValue = {};
       function getAll_PROMISE(signedInUser){
           return new Promise(function(resolve, reject){
              getValue = index.getAll(signedInUser);  
              getValue.onsuccess = function(event){
                  if(event.target.result){
                    alert("event.target. got result " + event.target.result);  
                    resolve(event.target.result);
                  }else{
                    alert("Event.target have not result");  
                    reject(undefined);
                  }
              }     
              getValue.onerror = function(event){
                reject(event.target.errorCode);
              }           
           });
       }
       (function(){
           try {
            includedDate.forEach(async function(eachDate){
                await getAll_PROMISE(currentSignedInUser).then((arrayOfObject) => {
                    foundNothing = false;
                    alert("foundNothing... "+foundNothing + arrayOfObject); //foundNothing is false here
                    arrayOfObject.forEach(function(usernameKey){
                        if(serializeDate(eachDate) == usernameKey.dateValueSaved){
                            console.log("foundDate: " + usernameKey.dateValueSaved + "wechi" +usernameKey.wechi + " mahtem: " + usernameKey.mahtem);
                        }
                    });
                }, (rejectReason) => {
                    alert("The promise didn't reply anything or it rejected! " + rejectReason);
                });
            });
           }catch(err){
                alert("Catching error inside catch block: " + err);
           }
       })();

使用Promise后，变量foundNothing不会保留其value事件！