C# 中事务的操作 (附实例)

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在很多场合比如电子交易会用到事务，在C#中，事务的操作非常简单。通过System.Data.SqlClient.SqlTransaction类实现。
SqlTransaction实例的获得：SqlConnection.BeginTransaction();
通过设置Command.Transaction属性在连接中注册事务
Command.Transaction = SqlConnection.BeginTransaction();
SqlTransaction.Commit();提交事务
SqlTransaction.Rollback();回滚事务

例如下面程序，ExecTrans函数执行事务，将用户xiaobai的年龄加1.

程序源代码 TansactionTest.cs

using System;
using System.Data.SqlClient;

public class TransactionTest ...{
    //MS Sql Server Connection String
    private string sqlStr = "Data Source=.;Integrated Security=SSPI";
    //Get MS Sql Server Connection.
    private SqlConnection GetCon() ...{
        return new SqlConnection(this.sqlStr);
    }

    //事务的执行
    private void ExecTrans() ...{
        SqlConnection con = this.GetCon();
        SqlCommand cmd = new SqlCommand();
        SqlTransaction trans = null;
        Console.WriteLine("Begin to Execute Transaction...");
        using (con) ...{
            con.Open();
            //事务实例的获得
            trans = con.BeginTransaction();
            try ...{
                cmd.Connection = con;
                cmd.Transaction = trans; //向SqlCommand注册事务
                cmd.CommandText = "use nyzhl";
                cmd.ExecuteNonQuery();
                cmd.CommandText = "update [users] set [age]=[age]+1 where uid=''xiaobai''";
                cmd.ExecuteNonQuery();
                //提交事务
                trans.Commit();
            }
            catch(Exception e) ...{
                //回滚事务
                trans.Rollback();
                Console.WriteLine("Error!Transaction has RolledBack. "+e.Message);
            }
            finally ...{
                if(con!=null) con.Close();
            }
        }
    }

    //Print data from Database
    private void WriteInfor() ...{
        SqlConnection con = this.GetCon();
        SqlCommand cmd = new SqlCommand();
        SqlDataReader sdr = null;

        cmd.Connection = con;
        Console.WriteLine("User Information(UserID, Age):");

        con.Open();
        cmd.CommandText = "use nyzhl";
        cmd.ExecuteNonQuery();
        cmd.CommandText = "select * from [users]";
        sdr = cmd.ExecuteReader();
        while(sdr.Read()) ...{
            string uid = sdr.GetString(0);
            //Sql Sever中的tinyint型在C#中对应Byte型(都占一个字节)
            int age = sdr.GetByte(1);
            Console.WriteLine(uid+" : "+age);
        }
        sdr.Close();
        sdr.Dispose();
        con.Close();
        con.Dispose();
    }

    //Entry of Application
    public static void Main() ...{
        TransactionTest test = new TransactionTest();
        test.WriteInfor();
        test.ExecTrans();
        test.WriteInfor();
    }
}
数据库及表结构

use master
go
create database nyzhl
go
use nyzhl
go
create table users
(
uid varchar(255) primary key,
age tinyint
)
go
insert into users values(''nyzhl'',22)
go
insert into users values(''xiaobai'',20)
go
文章出处：http://www.diybl.com/course/4_webprogram/asp.net/asp_netxl/2007125/90383.html