使用数据表 C# MVC 减慢页面加载速度

Question

I am trying to clean up some pages in my solution. The pages or tables load slower than i would like. I am using a view model and doing a Foreach on the page in a table and then using datatables to display. It seems that on the database side it loads each record 1 at a time and with 1000s of records it takes way to long to load. When i run the query in SQL it is instantly populated. I am looking for some help to clean the code up and see if there is anything here that can be changed to make it load faster. Since I am using the foreach in the page the DeferRender does not work. It does not matter to me if i use this or JavaScript, certainly server side coding is an option. In the controller the use of an array may work also but i do not know how to incorporate that with a view model. "db.Companys.ToArray();" works for pulling from the model but the ToArray doesn't work with a viewModel to my knowledge.

Below is my code.

Controller:

public ActionResult Index()
    {
        var data = (from temp in db.TopLvlJobs
                    join serial in db.SerialNumbers on temp.TopLvlJob equals serial.TopLvlJob
                    select new TopLvlJobsViewModels
                    {
                        PartNumber = temp.PartNumber,
                        Description = temp.Description,
                        ExtDescription = temp.ExtDescription,
                        Drawing = temp.Drawing,
                        IsDelete = false,
                        CreatedDate = DateTime.UtcNow,
                        UpgradeAvailable = temp.UpgradeAvailable,
                        TopLvlJob = temp.TopLvlJob,
                        SerialNumber = serial.SerialNumber

                    }).OrderBy(x => x.CreatedDate);

        return View(data);
    }

ViewModel:

public class TopLvlJobsViewModels
{
    [Key]
    [Display(Name = "TopLvlJob")]
    [Required]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public string TopLvlJob { get; set; }
    [Display(Name = "Description")]
    [Required]
    public string Description { get; set; }
    [Display(Name = "Ext Description")]
    [Required]
    public string ExtDescription { get; set; }
    [Display(Name = "Part Number")]
    [Required]
    public string PartNumber { get; set; }
    [Display(Name = "Drawing")]
    [Required]
    public string Drawing { get; set; }
    [UIHint("_IsStatus")]
    [Display(Name = "Upgrade Available ?")]
    [Required]
    public bool UpgradeAvailable { get; set; }

    public DateTime? CreatedDate { get; set; }

    public string CreatedBy { get; set; }

    public DateTime? UpdatedDate { get; set; }

    public string UpdatedBy { get; set; }

    public bool? IsDelete { get; set; }
    [Display(Name = "Serial")]
    public string SerialNumber { get; set; }
    public TopLvlJobs topsjobs { get; set; }

    public HttpPostedFileBase Pdfupload { get; set; }

    public virtual IEnumerable<SubJobs> SubJobs { get; set; }
    public virtual IEnumerable<Upgrades> Upgrade { get; set; }
}

JavaScript on .CHTML page

    $(document).ready(function () {
    //var oTableMenuPermission = "";
    //oTableMenuPermission = 
    $("#SubJobsListTable").dataTable({
        "bRetrieve": true,
        "bProcessing": true,
        "dom": 'lBfrtip',
        "buttons": [
            { extend: 'copyHtml5', exportOptions: { columns: ':visible' } }
            , { extend: 'excelHtml5', exportOptions: { columns: ':visible' } }
            , { extend: 'csvHtml5', exportOptions: { columns: ':visible' } }
            , { extend: 'pdfHtml5', exportOptions: { columns: ':visible' } }
            , { extend: 'print', exportOptions: { columns: ':visible' } }
            , 'colvis'
        ], columnDefs: [{ visible: false, targets: [3] }, { orderable: false, targets: [2, 3, 4, 5, 6, 7, 8] }],
        "pageLength": 10,
        "lengthMenu": [[5, 10, 25, 50, -1], [5, 10, 25, 50, "All"]],
    });
    //table.buttons().container()
    //    .appendTo($('.col-lg-8:eq(0)', table.table().container()));
});

I can give you anything else needed, I didn't post the whole CHTML page due to length, however it is just a basic Foreach in a table View.

Thanks for your help!

Answer 1

use IQueryable instead of IEnumerable and try

Querying data from a database, IEnumerable execute a select query on the server side, load data in-memory on a client-side and then filter data. Querying data from a database, IQueryable execute the select query on the server side with all filters.