不添加要插入移动数据库的第一个项目
2GD*_*ave 10 javascript jquery telerik kendo-ui jaydata
我在Telerik Platform移动应用程序中使用JayData.JayData的优秀人才解决了我想要做的事情:
http://jsfiddle.net/JayData/zLV7L/
var savefeedIfNotExists = function (feed) {
//create jQuery promise
console.log("create deferred for " + feed.FeedID)
var def = new $.Deferred();
//async thread
pnrDB.PNRFeeds.filter('it.FeedId == ' + feed.FeedID).count(function (count) {
console.log("Add Feed - " + feed.FeedName);
if (count == 0) {
var f = new PNRFeed({
FeedId: feed.FeedID,
FeedName: feed.FeedName,
ImageName: feed.ImageName,
FeedActive: feed.IsActive,
OrderNumber: parseInt(feed.OrderNumber) + 1
})
pnrDB.PNRFeeds.add(f);
console.log("Resolve for - " + feed.FeedName);
//promise.resolve() indicates that all async operations have finished
//we add the ADD/SKIP debug info to the promise
def.resolve("ADD");
console.log("Resolved - " + feed.FeedName);
} else {
//console.log('feed id not 0 - ' + f.FeedId);
def.resolve("SKIP");
}
});
//return promise in order to wait for the async result of local database query
return def.promise();
};
我已添加到此代码中,当我运行它时也使用他们的Kendo.js模块用于JayData(与kendo的kendo.js不同),它似乎在循环函数中创建第一个promise时中断脚本.这只在第一次运行脚本时发生 - 如果您要刷新以进行重新加载,则它会正确运行并且第一个项目将被插入.
在第二次加载时,似乎工作得很好,没有调用他们的JayData JayData模块:
因此,即使它看起来好像要添加第一个项目(ID 19),该项目也永远不会添加到数据库中.然而,当您重新加载相同的完整脚本时,它会再次被标记为添加并且不会被中断,因此它最终会进入数据库.
任何人有任何想法或事情要尝试？
如果您使用的是html5，那么您可以使用webSQL来执行数据操作，它提供了数据上的选择、插入、更新等所有功能。Web SQL规范定义了一个API，用于将数据存储在数据库中，可以使用SQL的变体来查询。
您可以使用以下功能，我已在我的英特尔 XDK 移动应用程序中使用了它
if you are using html5 then you can use webSQL to perform data operations,it provides all functions like select,insert,update on data
> The Web SQL specification defines an API for storing data in databases
> that can be queried using a variant of SQL. you can use like following
> function
<!-- begin snippet: js hide: false --><!DOCTYPE HTML>
<html>
<head>
<script type="text/javascript">
function insert(){
var db = openDatabase('mydb', '1.0', 'Test DB', 2 * 1024 * 1024);
var msg;
db.transaction(function (tx) {
var nam = document.getElementById("Tname").value;
var id = document.getElementById("Tid").value;
var name2 = "velocity";
tx.executeSql('CREATE TABLE IF NOT EXISTS APP (id unique, log)');
tx.executeSql('INSERT INTO APP (id, log) VALUES (?,?)',[id,nam]);
//tx.executeSql('INSERT INTO LOGS (id, log) VALUES (61,'+name2+')');
msg = '<p>Log message created and row inserted.</p>';
document.querySelector('#status').innerHTML = msg;
});
}
function readdata(){
var db = openDatabase('mydb', '1.0', 'Test DB', 2 * 1024 * 1024);
var id = document.getElementById("Tid").value;
db.transaction(function (tx) {
tx.executeSql('SELECT * FROM APP', [], function (tx, results) {
console.log("All rows:");
var len = results.rows.length, i;
msg = "<p>Found rows: " + len + "</p>";
document.querySelector('#status').innerHTML += msg;
for (i = 0; i < len; i++){
msg = "<p><b>Name :-" + results.rows.item(i).log +"<br/>Contact :-" +results.rows.item(i).id + "</b></p>";
msg = "<p><b>Name :-" + results.rows.item(i).log +"<br/>Contact :-" +results.rows.item(i).id + "</b></p>";
//var row = result.rows.item(i);
//msg = console.log(" " + row.contact + " " + row.nam);
document.querySelector('#status').innerHTML += msg;
}
}, null);
});
}
function ByContact(){
var db = openDatabase('mydb', '1.0', 'Test DB', 2 * 1024 * 1024);
var con = document.getElementById("Con").value;
db.transaction(function (tx) {
tx.executeSql('SELECT * FROM APP WHERE (id LIKE ?);',[con], function (tx, results) {
console.log("All rows:");
var len = results.rows.length, i;
msg = "<p>Found rows: " + len + "</p>";
document.querySelector('#status').innerHTML += msg;
for (i = 0; i < len; i++){
msg = "<p><b>Name :-" + results.rows.item(i).log +"<br/>Contact :-" +results.rows.item(i).id + "</b></p>";
msg = "<p><b>Name :-" + results.rows.item(i).log +"<br/>Contact :-" +results.rows.item(i).id + "</b></p>";
//var row = result.rows.item(i);
//msg = console.log(" " + row.contact + " " + row.nam);
document.querySelector('#status').innerHTML += msg;
}
}, null);
});
}
</script>
</head>
<body style="background-image:url('f.jpg');background-repeat:no-repeat;">
<h1 align="center"><font color="white">Contact Form</font></h1>
<div style="color:white">
<table align="center">
<tr>
<td>contact no</td>
<td><input type="text" id="Tid"/></td>
</tr>
<tr>
<td>Name</td>
<td><input type="text" id="Tname"/></td>
</tr>
<tr>
<td>
<button id="add" onclick="return insert();">Insert</button>
</td>
<td>
<button onclick="return readdata();" id="read">readdata</button>
</td>
<td>
</td>
</tr>
</table>
<table>
<tr>
<td>
<button onclick="return ByContact();" id="GetByContact">GetByContact</button>
</td>
<td>
<input type="text" id="Con"/>
</td>
</tr>
</table>
<div id="status" name="status"><font color="white">Your Data Will Show Here</font></div>
</div>
</body>
</html>您可以从 https://github.com/ccoenraets/backbone-directory/tree/master/localdb http://www.tutorialspoint.com/html5/html5_web_sql.htm获取更多信息
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