Concatenate all of the items under `JobDestination` in list produced

Question

What is the best way of concatenating the list produced by the GetWaypoints method? I'd like to concatenate all of the items under JobWaypoints and seperate them by a new line.

I cannot seem to figure out the best way of directly accessing the JobWaypoints item in the waypoints list I created.

Window.cs

List<JobComponent.JobList> waypoints = JobComponent.GetWaypoints(jobId);

JobComponents.cs

    public static List<JobList> GetWaypoints(int jobId)
    {
        // Get destination
        const string query = "SELECT address FROM waypoint " +
                             "WHERE id NOT IN(" +
                             "(SELECT MIN(ID) FROM waypoint where booking_id=@id)," +
                             "(SELECT MAX(ID) FROM waypoint where booking_id=@id)) " +
                             "AND booking_id=@id";
        var jobList = new List<JobList>();
        using (var cmd = new MySqlCommand(query, DbObject.Connection))
        {
            if (DbObject.Connection.State != ConnectionState.Open)
            {
                DbObject.OpenConnection();
            }
            cmd.Parameters.AddWithValue(("@id"), jobId);
            try
            {
                using (MySqlDataReader dataReader = cmd.ExecuteReader())
                {
                    while (dataReader.Read())
                    {
                        var item = new JobList
                        {
                            JobWaypoints = dataReader["address"] + ""
                        };
                        jobList.Add(item);
                    }
                    dataReader.Close();
                    DbObject.CloseConnection();
                    return jobList;
                }
            }
            catch (Exception ex)
            {
                ErrorHandlingComponent.LogError(ex.ToString());
                throw;
            }
        }
    }

Please explain what _exactly_ you want to do ("concatenating the list" is too vague) and what you have tried to do so. Is the method querying the database even relevant? Something with `string.Join()` and `waypoints.Select()` should do the trick. — CodeCaster, Feb 12 '15 at 15:14
Sorry. Basically what I do is run an SQL query and the results of the query are stored in a list. Now I want to convert that list into a string, inwhich item is seperated by a new line. — methuselah, Feb 12 '15 at 15:18
Please show the code that doesn't seem to be working. This being your 500+th question you should know that. See also [Using Linq to concatenate strings](http://stackoverflow.com/questions/217805/using-linq-to-concatenate-strings), [LINQ select one field from list of DTO objects to array](http://stackoverflow.com/questions/22539581/linq-select-one-field-from-list-of-dto-objects-to-array). — CodeCaster, Feb 12 '15 at 15:21
I can't seem to figure out how to access the `JobWaypoints` in the `waypoints` list. That's all I am really struggling with. In the past, I would cast `(JobComponent.GetWaypoints)` but this only seems to work in a situation when you've actually selected an item from the list. — methuselah, Feb 12 '15 at 15:27
There is no `JobWaypoints` in `waypoints`. You return a list of `JobList`, only having their `JobDestination` set. — CodeCaster, Feb 12 '15 at 15:32

score 1 · Accepted Answer · answered Feb 12 '15 at 16:12

I used the string.Join method. The following example will create a string with all JobWaypoints values with a comma (,) in between each value:

List<JobComponent.JobList> waypoints = JobComponent.GetWaypoints(jobId);
string s = string.Join(",", waypoints.Select(i => i.JobWaypoints));

Concatenate all of the items under `JobDestination` in list produced

1 Answers1