如何在程序中使用事务

[shjqk]

在程序中要执行一组SQL语句，需要用到事务
Database dbTestDB;
dbTestDB= DatabaseFactory.CreateDatabase(Conn_TestDB);
DbCommand dbCommand = dbTestDB.GetSqlStringCommand(sSql);
DbTransaction Dbtran = null;
//这样做不行，会报Object reference not set to an instance of an object.
Dbtran = dbCommand.Connection.BeginTransaction();
dbCommand.Transaction = Dbtran;
try
{
...
}
catch(...)
{
}
应该怎么做实现事务

[zzxap]

begin tran

[mykelly6]

try
{
...
Dbtran.Commit();//没有出错提交到数据库
}
catch(...)
{
Dbtran.Rollback();//出错了就回滚
}
例子：

conn = DBUtil.getConnection();
                SqlTransaction tran = conn.BeginTransaction();
                foreach (DataGridViewRow r in dataGridViewFile.SelectedRows)
                {
                    Enclo en = new Enclo();
                    en.E_url = r.Cells["e_url"].Value.ToString();
                    en.M_id = m_id;
                    en.deleteByURL(tran);//数据库操作
                }
                tran.Commit();
                tran.Dispose();
                DBUtil.closeConnection(conn);

[relive_qiankai]

begin Dbtran

[mykelly6]

internal void deleteByURL(SqlTransaction tran)
        {
            string sqlStr = "DELETE enclosure WHERE m_id = " + m_id + " AND e_url = '" + e_url +"'";
            SqlCommand cmd = new SqlCommand(sqlStr, tran.Connection, tran);
            cmd.ExecuteNonQuery();
        }

[shjqk]

但是我在
Dbtran = dbCommand.Connection.BeginTransaction();
会报Object reference not set to an instance of an object.

[shjqk]

up