/// <summary>
/// 通过实例，查询数据
/// </summary>
/// <typeparam name="T">需要返回数据类型</typeparam>
/// <param name="connection">对IDbConnection扩展</param>
/// <param name="commandText">SQL语句</param>
/// <param name="value">映射到SQL语句的实例</param>
/// <returns>T类型数据集合</returns>
public static IEnumerable<T> QueryByInstance<T>(this IDbConnection connection, string commandText, object value)
{
//Stopwatch watch = new Stopwatch();
List<T> resultCollection = null;
IDataReader reader = null;
SqlDelegate<T>.GetReaderInstance instance_func = null;
SqlDelegate<T>.GetCommandByInstance command_func = SqlDynamicCache.GetInstanceCommandDelegate<T>(commandText, value);
IDbCommand command = connection.CreateCommand();
command_func(ref command, value);
bool CloseFlag =( connection.State == ConnectionState.Closed );
try
{
if (CloseFlag){ connection.Open();}
reader = command.ExecuteReader(CommandBehavior.CloseConnection| CommandBehavior.SequentialAccess | CommandBehavior.SingleResult);
CloseFlag = false;
instance_func = SqlDynamicCache.GetReaderDelegate<T>(reader, commandText);
resultCollection = new List<T>(reader.FieldCount);
while (reader.Read())
{
//watch.Restart();
//T t = instance_func(reader);
//watch.Stop();
// System.Console.WriteLine("执行Reader缓存：" + watch.Elapsed);
resultCollection.Add(instance_func(reader));
}
while (reader.NextResul }
reader.Dispose();
reader = null;
return resultCollection;
}
public void Retrieval(string query, SqlDelegate pFunc)
{
lock (_obj)
{
if (OpenConnection() == true)
{
try
{
MySqlCommand cmd = new MySqlCommand(query, connection);
MySqlDataReader dataReader = cmd.ExecuteReader();
pFunc(dataReader);
dataReader.Close();
}
catch (MySqlException ex)
{
ExceptionCatch(ex);
}
finally
{
if (this.ConnOpend())
{
this.CloseConnection();
}
}
}
}
}
public static IEnumerable <T> QueryByObjects <T>(this IDbConnection connection, string commandText, params object[] values)
{
List <T> resultCollection = null;
SqlDelegate <T> .GetReaderInstance instance_func = null;
SqlDelegate <T> .GetCommandByObject command_func = SqlDynamicCache.GetObjectsCommandDelegate <T>(commandText, values);
IDbCommand command = connection.CreateCommand();
command_func(ref command, values);
bool CloseFlag = (connection.State == ConnectionState.Closed);
IDataReader reader = null;
try
{
if (CloseFlag)
{
connection.Open();
}
reader = command.ExecuteReader(CommandBehavior.CloseConnection | CommandBehavior.SequentialAccess | CommandBehavior.SingleResult);
CloseFlag = false;
instance_func = SqlDynamicCache.GetReaderDelegate <T>(reader, commandText);
resultCollection = new List <T>(reader.FieldCount);
while (reader.Read())
{
T tNode = instance_func(reader);
resultCollection.Add(tNode);
}
while (reader.NextResult())
{
}
reader.Dispose();
reader = null;
return(resultCollection);
}
finally
{
if (reader != null)
{
if (!reader.IsClosed)
{
try { command.Cancel(); }
catch { }
}
reader.Dispose();
}
if (CloseFlag)
{
connection.Close();
}
command?.Dispose();
}
}
/// <summary>
/// 通过多个实例查询满足条件的数据
/// </summary>
/// <typeparam name="T">需要返回数据的类型</typeparam>
/// <param name="connection">对IDbConnection扩展</param>
/// <param name="commandText">SQL语句</param>
/// <param name="values">映射到SQL语句的实例数组</param>
/// <returns>T类型集合</returns>
public static IEnumerable<T> QueryByInstances<T>(this IDbConnection connection, string commandText, object[] values)
{
List<T> resultCollection = new List<T>();
SqlDelegate<T>.GetReaderInstance instance_func = null;
SqlDelegate<T>.GetCommandByInstance command_func = SqlDynamicCache.GetInstanceCommandDelegate<T>(commandText, values[0]);
int i_length = values.Length;
IDbCommand command = connection.CreateCommand();
IDataReader reader = null;
bool CloseFlag = (connection.State == ConnectionState.Closed);
try
{
if (CloseFlag) { connection.Open(); }
for (int i = 0; i < i_length; i += 1)
{
command_func(ref command, values[i]);
reader = command.ExecuteReader(CommandBehavior.CloseConnection | CommandBehavior.SequentialAccess | CommandBehavior.SingleResult);
CloseFlag = false;
if (instance_func == null)
{
instance_func = SqlDynamicCache.GetReaderDelegate<T>(reader, commandText);
}
while (reader.Read())
{
T tNode = instance_func(reader);
resultCollection.Add(tNode);
}
while (reader.NextResult()) { }
reader.Dispose();
reader = null;
}
return resultCollection;
}
finally
{
if (reader != null)
{
if (!reader.IsClosed)
{
try { command.Cancel(); }
catch { }
}
reader.Dispose();
}
if (CloseFlag) connection.Close();
command?.Dispose();
}
}
public static object ExecuteScalarByObject <T>(this IDbConnection connection, string commandText, params object[] values)
{
SqlDelegate <ENull> .GetCommandByObject command_func = SqlDynamicCache.GetObjectsCommandDelegate <ENull>(commandText, values);
IDbCommand command = connection.CreateCommand();
bool CloseFlag = (connection.State == ConnectionState.Closed);
try
{
if (CloseFlag)
{
connection.Open();
}
command_func(ref command, values);
return(command.ExecuteScalar());
}
finally
{
connection.Close();
command?.Dispose();
}
}
