javascript - 在 Javascript PhoneGap 中一次又一次显示相同的结果

Question

我们在循环中得到相同的结果。如果有人能理解我在哪里犯了错误，请告诉我。请查看此屏幕截图以获得一个想法。

我尝试在很多地方发出警报，似乎一切都很顺利。但不知道为什么没有得到结果。 “executeSql”在循环中使用多个值时是否无法正常工作？

或者select查询有错误吗？请告诉我为什么会造成这样的问题？

   var db;
    var shortName = 'WebSqlDB';
    var version = '1.0';
    var displayName = 'WebSqlDB';
    var maxSize = 65535;


window.onload =  function(){

        document.addEventListener("deviceready",init,false);
    }

 function init(){

            if (!window.openDatabase) {
              alert('Databases are not supported in this browser.');
              return;
            } 

            db = openDatabase(shortName, version, displayName,maxSize); 

            db.transaction(function(tx){ 
            tx.executeSql( 'DROP TABLE post_details',nullHandler,nullHandler);    
            tx.executeSql( 'CREATE TABLE IF NOT EXISTS post_details(UserId INTEGER NOT NULL PRIMARY KEY, post_title TEXT NOT NULL, post_date TEXT NOT NULL,post_comment TEXT NOT NULL,post_content TEXT NOT NULL, post_categories TEXT NOT NULL, post_image TEXT)',[],nullHandler,errorHandler);
                },errorHandler,successCallBack);


            if(checkConnection() != "No network connection"){
                $.ajax({
                url: 'http://www.foduu.com/api/get_recent_posts/?callback=?',
                type: 'GET',
                dataType: 'json',
                success: function(data){
                    console.log(data);

                    var number_of_post = Object.keys(data.posts).length;

                    for(var i=0; i < number_of_post; i++){

                                        var ptitle = data.posts[i].title;
                                        var pdate = data.posts[i].date;
                                        var pccount = data.posts[i].comment_count;
                                        var pcontent = data.posts[i].content;
                                        var pcategories = data.posts[i].categories;
                                        var pimage = "my image";
                                        //alert(ptitle +","+ pdate +","+ pccount+","+ pcategories +","+ pimage);
                                        db.transaction(function(transaction) {
                                            transaction.executeSql('INSERT INTO post_details(post_title,post_date,post_comment,post_content,post_categories,post_image) VALUES (?,?,?,?,?,?)',[ptitle,pdate,pccount,"pcontent",pcategories,pimage],nullHandler,errorHandler);
                                        }); 
                    }


                    db.transaction(function(transaction) {
                        transaction.executeSql('SELECT * FROM post_details;', [],
                          function(transaction, result) {
                            $.each(result.rows,function(index){
                                var row = result.rows.item(index);


                                var post_single="<li class='post'>" + 
                                "<a href='#' class='post_more'></a>" +
                                "<div class='post_right_reveal'>" +
                                "<h4><a href='#' onclick='swiperParent.swipeTo(4);'>"+ row['post_title'] +"</a></h4>" +
                                "</div>" +
                                "<div class='post_right_unreveal'>" +
                                "Posted in <a href='#'>blog category</a>" +
                                "<span class='post_comments'>25 Comments</span>" +
                                "<a href='#' class='post_readmore' onclick='swiperParent.swipeTo(4);'>read more</a>" +
                                "</div>" +

                                   "<div class='post_left'>" +
                                       "<span class='day'>7</span>" +
                                       "<span class='month'>feb</span>" +
                                   "</div>" +
                                  "</li>";
                                   $('#posts-all').append(post_single);
                                   $('#posts-all').trigger('create');


                            });

                        });
                    },errorHandler,nullHandler);   

                },
                error: function(data){
                        alert("Can Not Fetch data From server");

                    }


                });

            }
            else
                {
                    alert("No Internet Connection"); 
                }

    }

function checkConnection() {
        var networkState = navigator.network.connection.type;

        var states = {};
        states[Connection.UNKNOWN]  = 'Unknown connection';
        states[Connection.ETHERNET] = 'Ethernet connection';
        states[Connection.WIFI]     = 'WiFi connection';
        states[Connection.CELL_2G]  = 'Cell 2G connection';
        states[Connection.CELL_3G]  = 'Cell 3G connection';
        states[Connection.CELL_4G]  = 'Cell 4G connection';
        states[Connection.NONE]     = 'No network connection';

        return states[networkState];
    }

function errorHandler(transaction, error) {
   alert('Error: ' + error.message + ' code: ' + error.code);

}

function successCallBack() {
   alert("DEBUGGING: success");
}

function nullHandler(){}; 

有什么方法可以在所有其他 JS 或 CSS 文件之前加载我的 main.js 文件吗？

我尝试执行多个executeSql，它工作得很好。但当我在 FOR 循环中使用它时，它只是一次又一次地给我相同的标题。如果需要的话我可以把代码放在github上供你尝试。

提前谢谢您!

Answer 1

好的问题解决了，我在 db.trasaction(..) 之外运行 FOR 循环，它应该在 tx.excuteSql(...) 上运行这解决了我的问题。

我很高兴自己找到了解决方案。 :)

谢谢!