Question

错误是从db中检索对象失败。例外0是例外，即提供给操作的数据不符合要求。我想根据输入字段中提供的日期检索date，pre，post的对象值。还有一个错误是报告未定义。请帮助..

<!DOCTYPE html>
<html manifest="manifest.webapp" lang="en">
<head>
  <meta charset="utf-8">
  <title>Diab</title>

  <!link rel="stylesheet" href="diab.css">

<script src="http://ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js"></script>




</head>
<body>
    <input type="date" id="date" >Date</input>
    <input type="number" id="pre">Pre</input>
    <input type="number" id="post">Post</input>

    <button id="add">Add</button>
    <button id="show">Show</button>
    <script type="text/javascript" src="diab3.js"></script>
</body>
</html>




$(document).ready(function() 
{
        var db;
        var openDb=function()
        {
            var request=indexedDB.open("diabetore2",2);
            request.onsuccess = function()
            {
                console.log("DB created succcessfully");
                db = request.result;
                console.log("openDB done!!");
                return db;
            };


            request.onerror=function(){
                alert("could not open db");
            };

            request.onupgradeneeded = function()
            { 
                var db= request.onsuccess();

            console.log("openDB.onupgradeneeded function");
            var store = db.createObjectStore("diab", {keyPath: 'date'});
            var dateIndex = store.createIndex("date", "date",{unique: true});

                // Populate with initial data.
                store.put({date: "june 1 2013",pre:70,post:70});
                store.put({date: "june 2 2013",pre:71,post:87});
                store.put({date: "june 3 2013",pre:72,post: 76});
                store.put({date: "june 8 2013",pre:73,post:75});
            };   
        };

        function getObjectStore(store_name,mode)
        {
            var tx=db.transaction(store_name,mode);
            return tx.objectStore(store_name);
        }

        function addItems(date,pre,post)
        {
            console.log("addition to db started");
            var obj={date:date,pre:pre,post:post};
            var store=getObjectStore("diab",'readwrite');
            var req;
            try
            {
                req=store.add(obj);
            }catch(e)
            {
                if(e.name=='DataCloneError')
                alert("This engine doesn't know how to clone");
                throw(e);
            }
            req.onsuccess=function(evt)
            {
                console.log("****Insertion in DB successful!!****");

            };
            req.onerror=function(evt)
            {
                console.log("Could not insert into DB");
            };

        }

        function getItems(date)
        {   var gdate=date;
            console.log("retrieval started from db");
            var store=getObjectStore("diab","readonly");    
            var index=store.index("date");

            var request=index.get(gdate);
            request.onsuccess=function()
            {
                var matching=request.result;
                if(matching !== undefined)
                {
                    //report(matching.pre,matching.post);
                    alert(matching.pre+ " , "+matching.post);

                }else
                    console.log("match not found");
                   //report (null);
            };

        }

          $("#add").click(function(){

                console.log("addEventListeners called...");

                console.log("add...");
                var date=document.getElementById('date').value;
                var pre=document.getElementById('pre').value;
                var post=document.getElementById('post').value;

                if(!date)
                {
                    alert("required field missing..");
                    return;
                }
                addItems(date,pre,post);

          });

          $("#show").click(function(){

            console.log("eventlistner called for retrieval..");
            console.log("retrieve");
            var date=$('date').val();
            /*if(!date)
                {
                    alert("required field missing..");
                    return;
                }*/
            getItems(date);
          });

        openDb();
        //addEventListners();
        //here();


});

Answer 1

检索字段的值可以通过id来完成:(使用id时不要忘记＃）

var date = $('#date').val();

这可能会导致问题，您使用date作为对象存储的键，因此在这种情况下，它需要是唯一的并且具有以下类型之一：DOMstring，array，date of date。未定义的含义将不被接受。

indexedDB中的检索失败

1 个答案: