Nhibernate操作原生SQL以及查询DataTable

使用Nhibernate时我们很方便实现实体映射，但是如果遇到复杂查询则显得力不从心，这是我们可以利用Nhibernate来操作原生sql来查询到DataTable来实现我们复杂的查询及其它操作。以下实例已经过调试，现与大家分享。

/// <summary>
/// 执行ExecuteNonQuery
/// </summary>
/// <param name="sql"></param>
public void ExecuteNonQuery(string sql)
{
ISession session = null;
ITransaction transaction = null;
try
{
session = NHibernateHelper.GetCurrentSession();
transaction = session.BeginTransaction();
IDbCommand command = session.Connection.CreateCommand();
transaction.Enlist(command);//注意此处要把command添加到事物中
command.CommandText = sql;
command.ExecuteNonQuery();
transaction.Commit();
}
catch (Exception ex)
{
if (transaction != null)
{
transaction.Rollback();
}
throw ex;
}
finally
{
if (session != null)
{
session.Close();
}
}
}

/// <summary>
/// 填充DataSet
/// </summary>
/// <param name="sql"></param>
/// <returns></returns>
public static DataSet ExecuteDataset(string sql)
{
ISession session = null;
DataSet ds = new DataSet();
try
{
session = NHibernateHelper.GetCurrentSession();
IDbCommand command = session.Connection.CreateCommand();
command.CommandText = sql;

IDataReader reader = command.ExecuteReader();
DataTable result = new DataTable();
//result.Load(reader);//此方法亦可
DataTable schemaTable = reader.GetSchemaTable();
for (int i = 0; i < schemaTable.Rows.Count; i++)
{
string columnName = schemaTable.Rows[i][0].ToString();
result.Columns.Add(columnName);
}
while (reader.Read())
{
int fieldCount = reader.FieldCount;
object[] values = new Object[fieldCount];
for (int i = 0; i < fieldCount; i++)
{
values[i] = reader.GetValue(i);
}
result.Rows.Add(values);
}
ds.Tables.Add(result);
}
catch (Exception ex)
{
Debug.Assert(false);
}
finally
{
if (session != null)
{
session.Close();
}
}
return ds;
}

/// <summary>
/// 填充DataSet（此方法亦可）
/// </summary>
/// <param name="sql"></param>
/// <returns></returns>
public DataSet ExecuteDataset(string sql)
{
ISession session = null;
DataSet ds = new DataSet();
try
{
session = NHibernateHelper.GetCurrentSession();
IDbCommand command = session.Connection.CreateCommand();
command.CommandText = sql;
SqlDataAdapter da = new SqlDataAdapter(cmd as SqlCommand);
da.Fill(ds);
}
catch (Exception ex)
{
Debug.Assert(false);
}
finally
{
if (session != null)
{
session.Close();
}
}
return ds;
}