SQl 事物处理
/// <summary>
/// SQL Server事务样本类,演示Sql的事务操作
/// 作者:李斌(Ｃａｍｕｓ)
/// </summary>
public class SQLServerTransactionDemo
{
private SQLServerTransactionDemo(){}
/// <summary>
/// 获取SQL Server事务样本类的实例方法
/// </summary>
/// <returns>SQL Server事务样本类的实例</returns>
public static SQLServerTransactionDemo GetHandle()
{
return new SQLServerTransactionDemo();
}
#region 运行SQL Server事务Run方法
/// <summary>
/// 运行SQL Server事务
/// </summary>
public void Run()
{
// 访问Microsoft SQL Server样本数据库Northwind,假设Microsoft SQL Server的sa密码为空
string connectionString=@"Server=(Local);Database=Northwind;UID=sa;PWD=;Persist Security Info=false;";
//创建Connection对象
System.Data.SqlClient.SqlConnection sqlConnection = null;
System.Data.SqlClient.SqlTransaction sqlTransaction = null;
try
{
sqlConnection = new System.Data.SqlClient.SqlConnection(connectionString);
sqlConnection.Open();//打开Connection
// 开始本地事务,Connection.BeginTransaction()
// IsolationLevel.ReadCommitted:
// 在正在读取数据时保持共享锁，以避免脏读，但是在事务结束之前可以更改数据，从而导致不可重复的读取或幻像数据。
sqlTransaction = sqlConnection.BeginTransaction(System.Data.IsolationLevel.ReadCommitted,"SQLTransaction"）;
//创建Command对象
System.Data.SqlClient.SqlCommand sqlCommand = sqlConnection.CreateCommand();
// 指派Connection和Transaction对象给Command对象
sqlCommand.Connection = sqlConnection;
sqlCommand.Transaction = sqlTransaction;
//开始执行事务,该事务由命令1 2 3组成.
// 执行数据库命令1
sqlCommand.CommandText = "Insert into Region (RegionID, RegionDescription) VALUES (200, \'Description\')";
sqlCommand.ExecuteNonQuery();
// 执行数据库命令2
sqlCommand.CommandText = "Insert into Region (RegionID, RegionDescription) VALUES (201, \'Description\')";
sqlCommand.ExecuteNonQuery();
// 执行数据库命令3!!!与命令1相同,会出错
sqlCommand.CommandText = "Insert into Region (RegionID, RegionDescription) VALUES (200, \'Description\')";
sqlCommand.ExecuteNonQuery();
// 提交事务
sqlTransaction.Commit();
Console.WriteLine("两条数据库命令已经执行完成."）;
}
catch(Exception e)
{
try
{
if(sqlTransaction != null)
{
// 回滚事务
sqlTransaction.Rollback("SQLTransaction"）;
}
}
catch (System.Data.SqlClient.SqlException ex)
{
// 回滚事务失败
if (sqlTransaction.Connection != null)
{
Console.WriteLine("执行回滚事务时出现 " + ex.GetType() + " 违例!" + ex.Message);
}
}
Console.WriteLine("在执行数据库命令时出现 " + e.GetType() + " 违例!" + e.Message);
Console.WriteLine("两条数据库命令均未完成."）;
}
finally
{
//关闭Connection
if(sqlConnection != null)
{
sqlConnection.Close();
}
}
}
#endregion
public static void Main(string[] args)
{
SQLServerTransactionDemo.GetHandle().Run();
}
}
