Question

让我们考虑以下数据：
数据表1：

item1   item2
1        1
1        2
1        3
2        1
2        4

数据表2：

item1    nameItem1
1        fred
2        sam

我正在尝试编写一个javascript查询，该查询首先会根据table1从item2检索数据。
然后，它将使用该结果中的item1，并在表2中搜索名称对于输出，我会得到以下结果：

item2     nameItem1
1         fred
1         sam

我正在使用parse.com作为我的数据库，并且在这方面失败了。以下是我的javascript代码示例：

var className = "seminarAttendance";   //change this to the appropriate class name

var query = new Parse.Query(className);

query.equalTo("StudentID", attendancesearch.studentID.value);

query.find({
    success: function(results) {
        if(results.length==0){

        alert("Sorry, there are no results that match your search.")
            {return;}}

        var w = window.open();
        w.document.write('<html><head><title>Result Table</title>');
        w.document.write('<link rel="stylesheet" href="http://netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css"  type="text/css" >');
        w.document.write('<link rel="stylesheet" href="tablesearch.css" type="text/css" />');           
        w.document.write(' </head><body><h3> Here are your search results!</h3><br/>');
        w.document.write(' Student # ' + attendancesearch.studentID.value + ' has attended ' +results.length + ' seminars <br>');
        w.document.write('<div class="search"><table class="table table-bordered table-condensed table-striped" >');
        w.document.write('<thead><tr><td><b>Seminar ID</b></td><td><b>Student ID</b></td><td><b>Time Period</b></td><td><b>Student ID</b></td><td><b>Student ID</b></td></tr></thead><tbody>');

        for (var i=0; i < results.length; i++){
            var object = results[i];

            var semid = object.get("SeminarID");
            var studid=object.get("StudentID");
            var timeper=object.get("timePeriodID");

            var semclass = "seminarTable";
            var query2 = Parse.Query(semclass);
            query2.equalTo("seminarID", semid);
            query2.first({

            success:  function(q2object){

            var test = q2object.get("seminarName");
            },
            });

            w.document.write('<tr>');
            w.document.write('<td>' + semid + '</td>');
            w.document.write('<td>' + studid + '</td>');
            w.document.write('<td>' + timeper + '</td>');
            w.document.write('<td>' + test + '</td>');
            w.document.write('</tr>');
        }
        w.document.write('</tbody></table></div></body></html>');
        w.document.close();

Answer 1

您不能在＆＃39;中使用＆＃39;循环。因为查询需要花费一些时间，这比执行＆＃39;要大得多。环。相反，你可以获取＆＃34; seminarTable＆＃34;的所有对象。将它们存储在另一个数组中（比如results1）。现在我们有结果和结果1数组，因此您可以手动搜索并放置条件。

var className = "seminarAttendance";   //change this to the appropriate class name

var query = new Parse.Query(className);

query.equalTo("StudentID", attendancesearch.studentID.value);

query.find({
  success: function(results) {
    if(results.length==0){

    alert("Sorry, there are no results that match your search.")
        {return;}}

    var w = window.open();
    w.document.write('<html><head><title>Result Table</title>');
    w.document.write('<link rel="stylesheet" href="http://netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css"  type="text/css" >');
    w.document.write('<link rel="stylesheet" href="tablesearch.css" type="text/css" />');           
    w.document.write(' </head><body><h3> Here are your search results!</h3><br/>');
    w.document.write(' Student # ' + attendancesearch.studentID.value + ' has attended ' +results.length + ' seminars <br>');
    w.document.write('<div class="search"><table class="table table-bordered table-condensed table-striped" >');
    w.document.write('<thead><tr><td><b>Seminar ID</b></td><td><b>Student ID</b></td><td><b>Time Period</b></td><td><b>Student ID</b></td><td><b>Student ID</b></td></tr></thead><tbody>');




    var semclass = "seminarTable";
    var query2 = Parse.Query(semclass);
    query2.find({
        success:  function(results1){
           //Do whatever you want here
            w.document.write('<tr>');
            w.document.write('<td>' + semid + '</td>');
            w.document.write('<td>' + studid + '</td>');
            w.document.write('<td>' + timeper + '</td>');
            w.document.write('<td>' + test + '</td>');
            w.document.write('</tr>');
        },
        });


    }
    w.document.write('</tbody></table></div></body></html>');
    w.document.close();

尝试使用一个查询的结果与parse.com中新查询的结果相结合 - javascript

1 个答案: