Generic Data Reader causing memory leak - memory

Question

I created a generic method in reading sql statement, but I am having a memory leak whenever I do a select query and using while read.
Sample Query:
public CMItemPackagingType GetItemPackagingType(int itemID)
{
try
{
List<CommandParameter> param = new List<CommandParameter>();
StringBuilder sb = new StringBuilder();
using (BaseConnection db = new BaseConnection())
{
sb.Append("SELECT RATIO, PACKAGING_TYPE_CODE FROM ITEM_PACKAGING_TYPE WHERE ROUND_UP = 0.01 AND ITEM_ID = #itemID");
param.Add(new CommandParameter("#itemID", itemID));
using (var rs = db.ExecSQL(sb.ToString(), param.ToArray()))
{
CMItemPackagingType cmItemInfo = new CMItemPackagingType();
while (rs.Read())
{
CMItemPackagingType list = new CMItemPackagingType();
if (!rs.IsDBNull(0))
list.Ratio = Convert.ToInt32(rs.GetValue(0));
if (!rs.IsDBNull(1))
list.PackagingTypeCode = rs.GetValue(1).ToString();
cmItemInfo.ItemPackagingTypeList.Add(list);
}
return cmItemInfo;
}
}
}
catch (Exception ex)
{
GlobalFramework.HandleException(ex);
}
return null;
}
Generic Reader:
public DbDataReader ExecSQL(string sqlStmt, CommandParameter[] param)
{
List<MySqlParameter> p = ParameterMySql(param);
_mySqlConn = new MySqlConnection(szConnect);
if (_mySqlConn.State == ConnectionState.Open)
{
_mySqlConn.Close();
}
_mySqlConn.Open();
_mySqlComm = new MySqlCommand(sqlStmt, _mySqlConn);
_mySqlComm.Parameters.AddRange(p.ToArray());
MySqlDataReader reader = _mySqlComm.ExecuteReader();
return reader;
}

Answer 1

I'm assuming the BaseConnection is a wrapper around a SqlConnection and _mySqlConn is an instance of BaseConnection. I suspect the issue is that you are opening and closing the connection in ExecSQL and at the same time have a using statement around BaseConnection creating this leak. I would refactor your code with proper placement of using statements to ensure correct disposal of the objects and freeing of resources.
Example
var query = "YOUR QUERY";
using (var connection = new SqlConnection("YOUR CONNECTION STRING"))
{
using (var command = new SqlCommand(query, connection))
{
await connection.OpenAsync();
using (var reader = await command.ExecuteReaderAsync())
{
if (reader != null)
{
while (await reader.ReadAsync())
{
// your logic
}
}
} // reader closed and disposed up here
} // command disposed here
} //connection closed and disposed here
}
Also notice how I'm using the async versions of the ADO.NET methods. Async commands are critical in achieving scale, throughput, and latency.
I recommend you use Dapper over trying to develop a generic data reader and writing all the boilerplate ADO.NET code yourself.