I want to refactor this Method into an Asynchronous Task

Question

I would like to refactor the below method that's loading a Model to be Asynchronous. I'm new to Asynchronous Tasks and would appreciatiate any guidance. Thanks !

public List<T> LoadData<T,U>(string sqlStatement, U parameters, string connectionString)

{

using IDbConnection connection=new SQLiteConnection(connectionString)

List<T> rows=connection.Query<T>(sqlStatement, parameters).ToList();

return rows;

}

var output=_db.LoadData<PayerListModel, dynamic>(sql, new {Filter=$"%{filter}%"}, connString);

return output;

Answer 1

public async Task<List<T>> LoadDataAsync<T, U>(string sqlStatement, U parameters, string connectionString) {
	using IDbConnection connection = new SqliteConnection(connectionString);

	IEnumerable<T> rows = await connection.QueryAsync<T>(sqlStatement, parameters);

	return rows.ToList();
}

var output = await _db.LoadDataAsync<PayerListModel, dynamic>(sql, new { Filter = $"%{filter}%" }, connString);

return output;

The first thing you'll want to do is use the QueryAsync variant of the Query method provided by Dapper, which will return a Task<IEnumerable<T>> instead of IEnumerable<T>.

Also as LoadData needs to await the response of this in order to .ToList() it you'll need to mark the method as async. Just for completion I've just renamed LoadData to LoadDataAsync, which is the convention used when you have a Task<...> returning method.