Reading from IEnumerable and adding items dynamically to List using foreach in c#

Question

I'm using a stored proc(Dapper) to fetch data in an IEnumerable. To screen some unwanted characters and remove leading/trailing spaces, I have created a foreach loop, and then add the data to a List.

The following code is working and giving desired results, but I'm not sure if I'm doing it the right way or if there's a better way of doing it. Particularly, I'm sure if I'm initializing class appropriately and then adding to list.

public class LoadBOUserLogin
    {
        public string LOGIN_ID { get; set; }

        public string EMP_ID { get; set; }

        public string CODE { get; set; }
        public LoadBOUserLogin() { }
        public LoadBOUserLogin(string LOGIN_ID, string EMP_ID, string CODE)
        {
            this.CODE = CODE;
            this.LOGIN_ID = LOGIN_ID;
            this.EMP_ID = EMP_ID;
        }

    }  

private static IEnumerable<BOUserLogin> LoadBOUserLogin()
        {
            IEnumerable<DTO.BOUserLogin> items = new List<DTO.BOUserLogin>(0);

            var userLoginList = new List<BOUserLogin>();
            var userLogin = new BOUserLogin(); //initializing class
            try
            {

                string strQuery = @"[dbo].[BOUSER_SEL_Login]";


                using (SqlConnection con = new SqlConnection(Connections.GetConnectionString()))
                {
                    
                    items = con.Query<DTO.BOUserLogin>(strQuery, commandTimeout: 120, commandType: System.Data.CommandType.StoredProcedure);
                }

        //removing unwanted charaters and trim
                foreach (var x in items)
                {
                   
                    userLogin.LOGIN_ID = Regex.Replace(x.LOGIN_ID ?? string.Empty, @"[^\u0009\u000A\u000D\u0020-\u007E]", string.Empty).Trim();
                    userLogin.CODE = Regex.Replace(x.CODE ?? string.Empty, @"[^\u0009\u000A\u000D\u0020-\u007E]", string.Empty).Trim();
                    userLogin.EMP_ID = Regex.Replace(x.EMP_ID ?? string.Empty, @"[^\u0009\u000A\u000D\u0020-\u007E]", string.Empty).Trim();

                    userLoginList.Add(new BOUserLogin(userLogin.LOGIN_ID, userLogin.CODE, userLogin.EMP_ID));
                    
                }

            }
            catch (Exception ex)
            {
        throw ex;
            }
            
            return userLoginList;
        }

Answer 1

Close! First, I think your class should be named BOUserLogin, right?

public class BOUserLogin
{
    public string LOGIN_ID { get; }
    public string EMP_ID { get; }
    public string CODE { get; }

    public BOUserLogin() { }

    public BOUserLogin(string LOGIN_ID, string EMP_ID, string CODE)
    {
        this.CODE = CODE;
        this.LOGIN_ID = LOGIN_ID;
        this.EMP_ID = EMP_ID;
    }
}

Then your LoadBOUserLogin method needs a couple of minor changes, which I have commented in the code below:

private static IEnumerable<BOUserLogin> LoadBOUserLogin()
{
    IEnumerable<DTO.BOUserLogin> items = new List<DTO.BOUserLogin>(0);

    var userLoginList = new List<BOUserLogin>();

    // This is not required
    // var userLogin = new BOUserLogin(); //initializing class

    try
    {
        string strQuery = @"[dbo].[BOUSER_SEL_Login]";

        using (SqlConnection con = new SqlConnection(Connections.GetConnectionString()))
        {
            items = con.Query<DTO.BOUserLogin>(strQuery, commandTimeout: 120, commandType: System.Data.CommandType.StoredProcedure);
        }

        // Removing unwanted characters and trim
        foreach (var x in items)
        {
            // Assign the results to variables...
            var loginId = Regex.Replace(x.LOGIN_ID ?? string.Empty, @"[^\u0009\u000A\u000D\u0020-\u007E]", string.Empty).Trim();
            var code = Regex.Replace(x.CODE ?? string.Empty, @"[^\u0009\u000A\u000D\u0020-\u007E]", string.Empty).Trim();
            var empId = Regex.Replace(x.EMP_ID ?? string.Empty, @"[^\u0009\u000A\u000D\u0020-\u007E]", string.Empty).Trim();

            // ...and use the variables to instantiate the BOUserLogin class.
            userLoginList.Add(new BOUserLogin(loginId, code, empId));
        }
    }
    catch (Exception ex)
    {
        throw ex;
    }

    return userLoginList;
}

Finally, the catch has a couple of issues, which I will leave for you to investigate :)

Hint 1: Search for 'rethrow to preserve stack trace'.

Hint 2: Is the catch actually doing anything?