Work around for Generics and Dynamic arguments

Question

I'm trying to write a wrapper to hide much of the code I find myself repeating for each db call in Dapper. (namely the Sql Connection, try, default catch and finally) Essentially I would like to do something like the following code but I understand that because of there being a dynamic parameter I can't use generics int this way.

The way it is I get the error:

Consider casting the dynamic arguments or calling the extension method without the extension method syntax (refering to the conn.Query method)

Is there a way to refactor my ExecuteQuery or to something like it that works?

public abtract class IDbAccessService
{
   public LogService Logger { get; set; }

   public virtual IEnumerable<T> ExecuteQuery<T>(string sql, dynamic param, string connString)
      where T : BaseModel
   {
      using (var conn = DataAccessHelpers.GetOpenConnection(connString))
      {
         try
         {
            return conn.Query<T>(sql, param).ToList<T>();
         }
         catch (Exception ex)
         {
            Logger.Logger.Error(ex.Message, ex);
            throw ex;
         }
      }
   }
}

Answer 1

Extension methods cannot be dynamically dispatched. So call it without extension method syntax:

static IEnumerable<T> ExecuteQuery<T>(string sql, dynamic param, string connStr)
    where T : BaseModel
{
    using (var conn = DataAccessHelpers.GetOpenConnection(connStr))
    {
        return SqlMapper.Query(conn, sql, param).ToList<T>();
    }
}

Also you have useless logging which creates multiple log entries for single error, and useless connection disposing (it is done automatically by using block).

Tips for exception handling:

• Handle exception and log it
• Wrap exception in high-level exception and throw that wrapper (caller will handle that high-level exception, or will also wrap it)
• Do not catch exception (caller will do first or second option)