如何使用选定属性在动态表下拉列表中显示选定选项答案

【问题标题】：How to use selected attribute to show selected option in dynamic table dropdown list如何使用选定属性在动态表下拉列表中显示选定选项
【发布时间】：2020-07-15 08:51:36
【问题描述】：

以下代码用于为“学生详细信息”表中的“编辑”模型发送数据。我想在通过 AJAX 请求传递的下拉列表中显示选定的选项。它会将值传递给表格，但不显示选定的选项。

function fetchDetails(studentId = "") {
    if (studentId == "") {
        studentId = "all";
    }

    editTable = $('#edit_table').DataTable();
    var editTable;

    editTable.clear().draw();

    $.ajax({
        url: "{{ url('register_details') }}/" + studentId,
        method: 'GET',
        dataType: 'json',
        success: function(data, textStatus, jqXHR) {
            for (var i = 0; i < data.length; i++) {
                editTable.row.add([
                    data[i].id,
                    '<td><select class="form-control form-control-alternative" name="stud[' + data[i].id + '][student_id]" value="' + data[i].student_group_id + '"><option value="">Select Student Type</option>@foreach ($students as $studentType)@if ($studentType->student_group_id == 1 || $studentType->student_group_id == 2 || $studentType->student_group_id == 5)<option value="{{ $studentType->id }}">{{ $studentType->ledger_name }}</option>@endif @endforeach</select></td>',
                    '<td><input type="number" class="form-control form-control-alternative age" name="stud[' + data[i].id + '][age]" min="0" step="any" placeholder="0.00" value="' + data[i].age + '" /></td>'
                ]).draw(true);
            }
        }
    })
}

【问题讨论】：

你不能在 JS 中使用刀片指令
但它的工作只是质疑如何获得选定的选项

标签： jquery ajax laravel

【解决方案1】：

function fetchDetails(studentId = "") {
    if (studentId == "") {
        studentId = "all";
    }

    editTable = $('#edit_table').DataTable();
    var editTable;

    editTable.clear().draw();

    $.ajax({
        url: "{{ url('register_details') }}/" + studentId,
        method: 'GET',
        dataType: 'json',        
        success: function(data, textStatus, jqXHR) {
            console.log(data);
            for (var i = 0; i < data.length; i++) {
                console.log(data[i].student_group_id);
                editTable.row.add([
                    data[i].id,
                    '<td><select class="form-control form-control-alternative" id="student_group'+data[i].id+'" name="stud[' + data[i].id + '][student_id]" value="' + data[i].student_group_id + '"><option value="">Select Student Type</option>@foreach ($students as $studentType)@if ($studentType->student_group_id == 1 || $studentType->student_group_id == 2 || $studentType->student_group_id == 5)<option value="{{ $studentType->id }}">{{ $studentType->ledger_name }}</option>@endif @endforeach</select></td>',
                    '<td><input type="number" class="form-control form-control-alternative age" name="stud[' + data[i].id + '][age]" min="0" step="any" placeholder="0.00" value="' + data[i].age + '" /></td>'
                ]).draw(true);

                $("#student_group"+data[i].id+"").val(data[i].student_group_id);
            }
        }
    })
}

【讨论】：