Question

如何根据LINQ to SQL中的特定ID更新记录？

Answer 1

LINQ是一个查询工具（Q = Query） - 所以除了通过（面向对象的）数据上下文（在LINQ-to-SQL的情况下）之外，没有神奇的LINQ方法来更新单行。要更新数据，您需要获取数据，更新记录并提交更改：

using(var ctx = new FooContext()) {
    var obj = ctx.Bars.Single(x=>x.Id == id);
    obj.SomeProp = 123;
    ctx.SubmitChanges();
}

或者编写一个在TSQL中执行相同操作的SP，并通过数据上下文公开SP：

using(var ctx = new FooContext()) {
    ctx.UpdateBar(id, 123);
}

Answer 2

public bool UpdateCustomerIno(CustomerInfo toUpdate)
{
    bool successfullySaved = false;

    var db = new DataClasses1DataContext();
    try
    {
        var dbCstInfo = db.CustomerInfos
            .Where(w => w.CustomerID == toUpdate.CustomerID)
            .SingleOrDefault();

        if (dbCstInfo != null)
        {
            dbCstInfo.FirstName = toUpdate.FirstName;
            dbCstInfo.LastName = toUpdate.LastName;
            db.SubmitChanges();
            successfullySaved = true;
        }
    }
    catch {
        successfullySaved = false;
    }
    return successfullySaved;
}

Answer 3

更新

NorthwindDataContext db = new NorthwindDataContext();

Product product = db.Products.Single(p => p.ProductName == "Toy 1");

product.UnitPrice = 99;
product.UnitsInStock = 5;

db.SubmitChanges();

插入

Dim db As New NorthwindDataContext

' Create New category and Products
Dim category As New Category
category.CategoryName = "Scott's Toys"

Dim product1 As New Product
category.ProductName = "Toy 1"

Dim product2 As New Product
category.ProductName = "Toy 2"

Answer 4

缺乏更详细的信息：

using(var dbContext = new dbDataContext())
{
    var data = dbContext.SomeTable.SingleOrDefault(row => row.id == requiredId);
    if(data != null)
    {
        data.SomeField = newValue;
    }
    dbContext.SubmitChanges();
}

Answer 5

AdventureWorksDataContext db = new AdventureWorksDataContext();
db.Log = Console.Out;

// Get hte first customer record
Customer c = from cust in db.Customers select cust where id = 5;
Console.WriteLine(c.CustomerType);
c.CustomerType = 'I';
db.SubmitChanges(); // Save the changes away

Answer 6

 DataClassesDataContext dc = new DataClassesDataContext();

 FamilyDetail fd = dc.FamilyDetails.Single(p => p.UserId == 1);

 fd.FatherName=txtFatherName.Text;
        fd.FatherMobile=txtMobile.Text;
        fd.FatherOccupation=txtFatherOccu.Text;
        fd.MotherName=txtMotherName.Text;
        fd.MotherOccupation=txtMotherOccu.Text;
        fd.Phone=txtPhoneNo.Text;
        fd.Address=txtAddress.Text;
        fd.GuardianName=txtGardianName.Text;

        dc.SubmitChanges();

Answer 7

我在一周前找到了解决方法。您可以使用带有“ExecuteCommand”的直接命令：

MDataContext dc = new MDataContext();
var flag = (from f in dc.Flags
                   where f.Code == Code
                   select f).First();
_refresh = Convert.ToBoolean(flagRefresh.Value);
if (_refresh)
{
    dc.ExecuteCommand("update Flags set value = 0 where code = {0}", Code);
}

在ExecuteCommand语句中，您可以直接发送查询，并使用您要更新的特定记录的值。

value = 0 - ＆gt; 0是记录的新值;

code = {0} - ＆gt;是您将发送过滤器值的字段;

代码 - ＆gt;是该领域的新价值;

我希望这个参考有所帮助。

使用LINQ to SQL进行更新

7 个答案: