Asp MVC: Daten vom SQL Server direkt in eine List ausgeben

Date 03.04.2018

Asp MVC: Daten vom SQL Server direkt in eine List<Typ> ausgeben

Normaler Aufruf: Hole Daten mit Linq-EF aus einer Datenbank-Tabelle

Nachteil: die Ergebnisse sind vom Typ var und müssen erst noch manuell in eine List<Datenmodel> überführt werden

var dsFollower = await _dbContext.tbl_User_Followers.Select(u => u.IDUser == IDOwner).ToListAsync();

Sql-Daten in Liste laden:

Mit dieser Datenabfrage leiten sie die Ergebnisse einer Datentabelle direkt in eine Liste vom gleichen Datenmodel-Typ.

Hierzu muss die Tabelle [tbl_User_Followers] vom Listen-Inhaltstyp: <User_FollowerModel> sein.

//< get Follower >

List<User_FollowerModel> list_Follower =

await _dbContext.tbl_User_Followers.Where(u => u.IDUser == IDOwner).ToListAsync();

//</ get Follower >

Ausgabe in der View

So kann man die Daten in der Anzeige View ausgeben

Asp Core MVC

Man durchläuft mit foreach(..) die Liste und gibt die Ergebnisse mit Html.Raw(text) aus

<p>

Follower: @Model.sumFollowers

foreach (var follower in Model.List_Followers)

{

}

</p>

View Beispiel

Ausgabe der Datei Readdy/Views/User/User_Page.cshtml

@model Readdy.Models.User_Page_ViewDataModel

ViewData["Title"] = "😀 User Page/" + Model.Ownername;

Layout = "~/Views/Shared/_Layout.cshtml";

}

<style>

.divMain {

-webkit-box-orient: vertical;

-webkit-box-direction: normal;

flex-direction: column;

vertical-align: top;

display: inline-block;

width: 80%;

/*max-width: 80%;*/

overflow-wrap: break-word;

overflow: auto;

margin: 0px;

margin-top: 2px;

padding: 10px;

background-color: rgba(250, 250, 250, 0.9);

border-radius: 8px 8px 8px 8px;

}

/* resize images */

.divMain img {

max-width: 100%;

height: auto;

}

.divMain td {

width: auto;

max-width: 700px;

}

.divRight {

display: inline-block;

/*display: block;*/

/*float: right;*/

margin: 0;

padding: 0px;

background-color: rgba(235, 235, 235, 0.74);

}

.divList {

width: 100%;

}

.divItem {

width: 100%;

display: block;

padding: 4px;

margin-top: 10px;

box-shadow: 0 1px 2px 0 rgba(0,255,0,0.2), 0 0 0 1px rgba(0,0,0,0.1);

transition: box-shadow 1s ease-in-out;

border-radius: 2px;

outline: none;

background-color: rgba(255,255,255,1)

}

.divItem:hover {

background-color: rgba(182, 255, 0,0.5);

}

.divOwner {

width: 100%;

display: block;

padding: 4px;

margin-top: 10px;

outline: none;

font-size: x-small;

}

.divOwner:hover {

background-color: rgba(182, 255, 0,0.5);

}

</style>

► <img src="~/images/Ico/icoProfil.png" style="height:20px;vertical-align:text-bottom;">

: <a href="/user/User_Page/@Model.IDOwner" style="font-weight:bold ">@Model.Ownername </a>

</h3>

@*--------< divMain >--------*@

@*------< Image >--------*@

@*------</ Image >--------*@

@*------< Description >--------*@

<p>Started: @Model.dtCreate</p>

<p>

Follower: @Model.sumFollowers

foreach (var follower in Model.List_Followers)

{

}

</p>

<p>

Follows: @Model.sumFollows

foreach (var follows in Model.List_Follows)

{

}

</p>

<p>Views: @Model.sumViews</p>

<span>

Info:

@Model.Description

</span>

</div>

@*------</ Description >--------*@

@*------< Notes >--------*@

►<a href="~/notes/User_Notes/@Model.IDOwner">📃Notes</a>

@*------< Loop: Details >------*@

int iLoop = 0;

foreach (var note in Model.List_Notes)

{

iLoop++;

@*----< row >----*@

<a href="~/Notes/Details/@note.IDNote" title="@Html.DisplayFor(modelItem => note.DtEdit): @Html.DisplayFor(modelItem => note.Title)" style="text-decoration:none;display:block;">

if (iLoop < 3)

{

if (note.sumImages > 0)

{

</div>

}

@Html.DisplayFor(modelItem => note.Title)

</span>

@Html.DisplayFor(modelItem => note.DtEdit)

(👁@Html.DisplayFor(modelItem => note.sumViews))

</span>

</div>

</Div>

</a>

@*----</ row >----*@

}

</Div>

@*----</ Loop: Details >------*@

@*------</ Notes >--------*@

</div>

@*--------</ divMain >--------*@

Komplettes asp.Net Core MVC Beispiel

Zeigt: wie ruft man direct eine mit Linq und EF Entity Framework eine Tabelle von der SQL Server Datenbank ab in eine List<Datenmodel> Liste ab

using System;

using System.Collections.Generic;

using System.Linq;

using System.Threading.Tasks;

using Microsoft.AspNetCore.Mvc;

using Microsoft.EntityFrameworkCore;

using Readdy.Data;

using Readdy.Models;

using Microsoft.AspNetCore.Authorization;

using Microsoft.AspNetCore.Hosting;

using System.IO;

using Microsoft.AspNetCore.Http;

namespace Readdy.Controllers

{

public class UserController : Controller

{

#region Controller Init

private readonly ApplicationDbContext _dbContext;

private readonly IHostingEnvironment _hostingEnvironment;

public UserController(ApplicationDbContext dbContext, IHostingEnvironment hostingEnvironment)

{

//----< Init: Controller >----

_dbContext = dbContext;

_hostingEnvironment = hostingEnvironment;

//----</ Init: Controller >----

}

#endregion

public async Task<IActionResult> User_Page(long Id)

{

//-------------< User_Page_load() >-------------

//< init >

long IDOwner = Id;

//</ init >

//--< Get User ID >--

//internal referenz-Number for tracking in tables

long IDCurrent_User = await UserInfo_Methods.getIDUser_as_Number(this.User, _dbContext);

//--</ Get User ID >--

//< content_logger >

await Counter_Logger.counter_Note_List_erhoehen(IDCurrent_User);

//</ content_logger >

//--< Get Linq.Query >--

//*gets last 10 Notes with View_Sum

var query = (from n in _dbContext.tbl_Notes

where n.IDUser == Id

orderby n.IDNote descending

select n).Take(20);

//--</ Get Linq.Query >--

//< get Owner >

var owner = await _dbContext.Users.SingleOrDefaultAsync(u => u.IDUser == IDOwner);

if (owner == null)

{

return Content("Owner not found");// NotFound();

}

//</ get Owner >

//< get Sums >

var userSums = await _dbContext.tbl_User_Sums.SingleOrDefaultAsync(u => u.IDUser == IDOwner);

//</ get Sums >

//< get Follower >

//var dsFollower = await _dbContext.tbl_User_Followers.Select(u => u.IDUser == IDOwner).ToListAsync();

List<User_FollowerModel> list_Follower = await _dbContext.tbl_User_Followers.Where(u => u.IDUser == IDOwner).ToListAsync();

//</ get Follower >

//< get Follows >

List<User_FollowerModel> list_Follows = await _dbContext.tbl_User_Followers.Where(u => u.IDFollower == IDOwner).ToListAsync();

//</ get Follows >

//--< fill Notes >--

List<NoteModel> list_Notes = new List<NoteModel>();

foreach (var row in query)

{

//--< Row to Data >--

//< correct >

string sShort = row.Text;

if (sShort.Length > 255) { sShort = sShort.Substring(0, 255); }

row.Text = sShort;

//</ correct >

//< Data >

NoteModel note = new NoteModel();

note = row;

//</ Data >

//< add >

list_Notes.Add(note);

//</ add >

//--</ Row to Data >--

}

//--</ fill Notes >--

User_Page_ViewDataModel data = new User_Page_ViewDataModel();

data.List_Notes = list_Notes;

data.IDOwner = IDOwner;

data.Ownername = owner.UserName;

data.Description = owner.User_Description;

data.dtCreate = Convert_Methods.DateNull_to_Date(owner.dtCreated);

data.sumFollowers = Convert_Methods.IntNull_to_Int(owner.sumFollowers);

if (userSums == null)

{

data.sumViews = 0;

}

else

{

data.sumViews = Convert_Methods.IntNull_to_Int(userSums.intSumViews_Others); //User_SumModel

}

data.List_Followers = list_Follower ;

data.List_Follows = list_Follows;

//< out to view >

//return View(data_to_View);

return View("User_Page", data);

//</ out to view >

//-------------</ User_Page_load() >-------------

}