这篇文章主要介绍“LINQ To SQL的Transaction举例分析”,在日常操作中,相信很多人在LINQ To SQL的Transaction举例分析问题上存在疑惑,小编查阅了各式资料,整理出简单好用的操作方法,希望对大家解答”LINQ To SQL的Transaction举例分析”的疑惑有所帮助!接下来,请跟着小编一起来学习吧!
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不管你是由我的书中,或是MSDN、网站处得知,LINQ to SQL之DataContext于SubmitChanges函式执行时,就算不指定Transaction,DataContext都会自动启动一个 Transaction,在许多ORM中,这算是相当常见的设计。
不过,如果我不想要这个预设的LINQ To SQL Transaction呢?原因有很多,可能是为了减少Lock的时间,或是效能、资源等等,反正就是不想要这个预设行为就是了!只要简简单单的更新资料就好了。
可能吗?就目前的LINQ To SQL设计来说,这个行为是强制性的,且无可调整之空间,但!若要强渡关山也不是没交通工具,DataContext开了一个小口,让我们可以覆载 SubmitChanges函式,以此为起点,我利用了大量的Reflection技巧,让Transaction消失。
using System; using System.Data; using System.Data.Common; using System.Data.SqlClient; using System.Collections.Generic; using System.Linq; using System.Data.Linq; using System.Text; using System.Reflection; namespace ConsoleApplication35 { class Program { static void Main(string[] args) { NorthwindDataContext context = new NorthwindDataContext(); var item = (from s1 in context.Customers where s1.CustomerID == "VINET" select s1).FirstOrDefault(); if (item != null) item.ContactName = "VINET14"; Console.ReadLine(); context.DisableTransaction = true; context.SubmitChanges(); Console.ReadLine(); } } partial class NorthwindDataContext { public bool DisableTransaction { get; set; } private static MethodInfo _checkDispose = null; private static MethodInfo _checkNotInSubmitChanges = null; private static MethodInfo _verifyTrackingEnabled = null; private static MethodInfo _acceptChanges = null; private static MethodInfo _submitChanges = null; private static FieldInfo _conflicts = null; private static FieldInfo _isInSubmitChanges = null; private static PropertyInfo _services = null; private static Type _changeProcessorType = null; private static ConstructorInfo _ci = null; static NorthwindDataContext() { _checkDispose = typeof(DataContext).GetMethod("CheckDispose", BindingFlags.NonPublic | BindingFlags.Instance); _checkNotInSubmitChanges = typeof(DataContext).GetMethod("CheckNotInSubmitChanges", BindingFlags.NonPublic | BindingFlags.Instance); _verifyTrackingEnabled = typeof(DataContext).GetMethod("VerifyTrackingEnabled", BindingFlags.NonPublic | BindingFlags.Instance); _acceptChanges = typeof(DataContext).GetMethod("AcceptChanges", BindingFlags.NonPublic | BindingFlags.Instance); _conflicts = typeof(DataContext).GetField("conflicts", BindingFlags.NonPublic | BindingFlags.Instance); _isInSubmitChanges = typeof(DataContext).GetField("isInSubmitChanges", BindingFlags.NonPublic | BindingFlags.Instance); _changeProcessorType = typeof(DataContext).Assembly.GetType( "System.Data.Linq.ChangeProcessor"); _services = typeof(DataContext).GetProperty("Services", BindingFlags.NonPublic | BindingFlags.Instance); _ci = _changeProcessorType.GetConstructor( BindingFlags.NonPublic | BindingFlags.Instance, null, new Type[] { typeof(DataContext).Assembly.GetType("System.Data.Linq.CommonDataServices"), typeof(DataContext) }, null); _submitChanges = _changeProcessorType.GetMethod("SubmitChanges", BindingFlags.NonPublic | BindingFlags.Instance); } public override void SubmitChanges(System.Data.Linq.ConflictMode failureMode) { if (DisableTransaction) { _checkDispose.Invoke(this, null); _checkNotInSubmitChanges.Invoke(this, null); _verifyTrackingEnabled.Invoke(this, null); ((ChangeConflictCollection)_conflicts.GetValue(this)).Clear(); try { _isInSubmitChanges.SetValue(this, true); object processor = _ci.Invoke(new object[] { _services.GetValue(this, null), this }); _submitChanges.Invoke(processor, new object[] { failureMode }); _acceptChanges.Invoke(this, null); } finally { _isInSubmitChanges.SetValue(this, false); } } else base.SubmitChanges(failureMode); } } }
处理完毕,我个人是觉得,应该把LINQ To SQL Transaction以Session概念处理,如Hibernate。
到此,关于“LINQ To SQL的Transaction举例分析”的学习就结束了,希望能够解决大家的疑惑。理论与实践的搭配能更好的帮助大家学习,快去试试吧!若想继续学习更多相关知识,请继续关注创新互联网站,小编会继续努力为大家带来更多实用的文章!