SqlTransaction 数据库编程事务使用示例

在提交或回滚 SqlTransaction 时，应始终使用 Try/Catch 进行异常处理。如果连接终止或事务已在服务器上回滚，则 Commit 和 Rollback 都会生成 InvalidOperationException。

下面的示例创建一个 SqlConnection 和一个 SqlTransaction。此示例还演示如何使用 BeginTransaction、Commit 和 Rollback 等方法。出现任何错误时事务都会回滚。Try/Catch 错误处理用于处理尝试提交或回滚事务时的所有错误。

using System;
 using System.Configuration;
 using System.Data.SqlClient;
 using System.Transactions;
 ...
 
 protected void Page_Load(object sender, EventArgs e)
         {
 
 using (SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnStr"].ToString()))
             {
                 conn.Open();
                 SqlTransaction _transaction = conn.BeginTransaction();                  
 try
                 {
                     SqlCommand _cmd = new SqlCommand("Insert Into T_Test(F_Name) values(@Name)",conn);
                     _cmd.Parameters.Add(new SqlParameter("@Name", "Test1"));
                     _cmd.Transaction = _transaction;
                     _cmd.ExecuteNonQuery();
 
                     _cmd.Parameters.Clear();
                     _cmd.Parameters.Add(new SqlParameter("@Name", "Test2" + new String('2', 100)));
                     _cmd.ExecuteNonQuery();//F_Name为Nvarchar(50)，这里会报错
 
                     _transaction.Commit();
 
                     Response.Write("二条记录已经成功入库!");
                 }
 catch (Exception ex)
                 {
                     Response.Write("发生错误：" + ex.Message.ToString());
 try
                     {
                         _transaction.Rollback();
                         Response.Write("<br/>事务已成功回滚!");
                     }
 catch (Exception ex2)
                     {
                         Response.Write("<br/>回滚失败：" + ex2.Message.ToString());
                     }
                 }
                 _transaction.Dispose();
             }
         }  

如果换成时下流行的Linq To Sql写法，大致如下：

using (DataContext context = new DataContext(connStr))
             {
 
                 SqlConnection conn = new SqlConnection();                   
 if (context.Connection != null && context.Connection.State!=ConnectionState.Open) context.Connection.Open();
 
                 context.Transaction = context.Connection.BeginTransaction();
 try
                 {
                     User user = new User();
                     user.Name = "aaaa";
                     users.Add(user);
                     context.SubmitChanges();
 
                     users.Remove(users.Single(u => u.Name == "aaaa"));
                     context.SubmitChanges();
 
                     context.Transaction.Commit();
                 }
 catch
                 {
 try
                     {
                         context.Transaction.Rollback();
                     }
 catch 
                     {
 //
...

                     }
                 }
             }