Question

需要帮助使用LinQ更新记录。

我尝试更新记录，但它没有显示在数据库中。

主键在db和LinQ dbml文件中设置。

以下是代码：

RPHContrib _phContrib = new RPHContrib();
_phContrib.PHTableNo = phContrib.PHTableNo;
_phContrib.AmountFrom = phContrib.AmountFrom;
_phContrib.AmountTo = phContrib.AmountTo;
_phContrib.EmployeePH = phContrib.EmployeePH;
_phContrib.EmployerAmt = phContrib.EmployerAmt;
_phContrib.IsActive = phContrib.IsActive;
_phContrib.CreatedByNo = phContrib.CreatedByNo;
_phContrib.CreatedDate = phContrib.CreatedDate;
_phContrib.ModifiedByNo = SessionStateController.OnlineUserNo;
_phContrib.ModifiedDate = DateTime.Now;

LINQHelper.Instance.GenericDataContext<HRWizardDataContext>(GetDataContext(false));
LINQHelper.Instance.Update<RPHContrib>(_phContrib);

public bool Update<T>(T obj) where T : class, ICommon, new()
{
    using (var db = GetDBDataContext())
    {    
        db.Connection.Open();
        DbTransaction trans = db.Connection.BeginTransaction();
        db.Transaction = trans;

        // Populate object log                
        obj.IModifiedDate = DateTime.Now;

        try
        {
            Detach<T>(obj); // Detach LINQ entity from the original DataContext before attaching to the new one            
            db.GetTable<T>().Attach(obj, true);
            db.SubmitChanges();
            db.Transaction.Commit();
        }
        catch (Exception ex)
        {
            db.Transaction.Rollback();
            // TODO: Put error logging code here
            throw ex;
        }
        finally
        {
            if (db.Connection != null)
            {
                db.Connection.Close();
                db.Connection.Dispose();
            }
        }
    }
    return true;
}

Answer 1

当您添加新的记录用途InsertOnSubmit(Entity)时，在您调用SubmitChanges（）后，会自动更新您的对象上的任何自动编号（例如主要）。

更新实体时使用Attach(Entity)。在附加实体后对其进行更改。在将其附加到Context之前进行更改将不会触发Update SQL，因为上下文会认为没有任何内容可以更新。

Answer 2

您需要在insertonsubmit(obj);

之前submitchanges();

无法更新LINQ to SQL中的记录

2 个答案: