How to retrieve a single value from the database using Dapper

Either you can use ExecuteScalarAsync or Single() with ExecuteScalarAsync you can retrieve a single value from database using Dapper.

short status;
using (var sqlConnection = new SqlConnection(connectionString))
{
  var parameters = new DynamicParameters();
  parameters.Add("@ID", ID, DbType.Int32, ParameterDirection.Input);

  await sqlConnection.OpenAsync();
  status = await sqlConnection.ExecuteScalarAsync<short>("SELECT [StatusID] FROM     [MyTable] WHERE [ID] = @ID", parameters, commandTimeout: _sqlCommandTimeoutInSeconds);
}

Single() can be used in this way

short status;
using (var sqlConnection = new SqlConnection(connectionString))
{
  var parameters = new DynamicParameters();
  parameters.Add("@ID", ID, DbType.Int32, ParameterDirection.Input);

  await sqlConnection.OpenAsync();
  status = await sqlConnection.QueryAsync<short>("SELECT [StatusID] FROM [MyTable] WHERE [ID] = @ID", parameters, commandTimeout: _sqlCommandTimeoutInSeconds).Single();
}

FYI, Dapper has now added both QuerySingle and QuerySingleAsync as well as their corresponding OrDefault variants... usage for QuerySingleOrDefaultAsync is:

await connection.QuerySingleOrDefaultAsync<short>(sql);

You should use ExecuteScalar:

status = await sqlConnection.ExecuteScalarAsync<short>("SELECT [StatusID] FROM [MyTable] WHERE [ID] = @ID", parameters, commandTimeout: _sqlCommandTimeoutInSeconds)