尝试使用parse.com-javascript中一个查询的结果与新查询的结果组合

Trying to use results from one query to combine with results from new query in parse.com - javascript

本文关键字：结果 查询 一个 组合 新查询 parse com-javascript      更新时间：2023-09-26

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，它将首先从基于item2的table1中检索数据
然后，它将使用该结果中的item1，并在表2中搜索该名称
对于输出，我会得到以下内容：

item2     nameItem1
1         fred
1         sam

我正在使用parse.com作为我的数据库，但在这方面失败得很惨。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();

不能在'for'循环中调用query2。因为查询需要一些时间，这比执行"for"循环要长得多。相反，您可以获取"seminarTable"类的所有对象，并将它们存储在另一个数组中（比如results1）。现在我们有了results和results1数组，所以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();
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