How to update the data in database using linq

Question

I have learning C# MVC using linq. Now I don't know how to save the updated data in database

How to update the data?

public ActionResult Edit(Table_2 emp)
{
    List<Table_2> objemp = new List<Table_2>();
    using (var dbs = new guruEntities())
    {
        var name = emp.name;
        var dep = emp.dprmt;
        var query = from n in dbs.Table_2.Where(n => n.name == name && n.dprmt == dep)
            orderby n.id
            select n;
        dbs.SaveChanges();
    }

    return RedirectToAction("Index");
}

View:

<div class="form-horizontal">
<h4>Table_2</h4>
<hr />
@Html.ValidationSummary(true, "", new { @class = "text-danger" })
@Html.HiddenFor(model => model.id)
<div class="form-group">
    @Html.LabelFor(model => model.name, htmlAttributes: new { @class = "control-label col-md-2" })
    <div class="col-md-10">
        @Html.EditorFor(model => model.name, new { htmlAttributes = new { @class = "form-control" } })
        @Html.ValidationMessageFor(model => model.name, "", new { @class = "text-danger" })
    </div>
</div>
<div class="form-group">
    @Html.LabelFor(model => model.dprmt, htmlAttributes: new { @class = "control-label col-md-2" })
    <div class="col-md-10">
        @Html.EditorFor(model => model.dprmt, new { htmlAttributes = new { @class = "form-control" } })
        @Html.ValidationMessageFor(model => model.dprmt, "", new { @class = "text-danger" })
    </div>
</div>
<div class="form-group">
    <div class="col-md-offset-2 col-md-10">
        <input type="submit" value="Save" class="btn btn-default" />
    </div>
</div>
</div>

I don't know how to get the user data from textbox and to get saved in the database

Answer 1

As you said you just want to update records in database. then first of all get records from the database which you want to update records like below

public ActionResult Edit(Table_2 emp)
{
      var table2 = _dbContext.Table_2.Where(x => x.Id == emp.id).FirstOrDefault(); //SingleOrDefault() also used.
      if (table2 == null)
      {
           throw new Exception("not found");
      }
       table2.name = emp.name;
       table2.dprmt = emp.dep;
       dbs.SaveChanges();
       return RedirectToAction("Index");
}

first get records from database and update that records and call SaveChanges() . and if you need to add new records into database then create first entity like

Table_2 entity = new Table_2();
        entity.id = 1;
        entity.name = "name";
        entity.dprmt = "dept";
        _dbContext.Table_2.Add(entity)
        dbs.SaveChanges();

you can save and update into database. let me know if any questions :)

Answer 2

you are using the "query" variable to retrieve data from a data store (I assume Entity Framework). however, once you fetch the data, you need to update it. it should be something like

query.name = "new name";

and then when you call save changes, EF will pick up the change and update the DB.

PS:

the vars you created "name" and "deps" are redundant. you can update the entity directly once you get it from the context.