SQL | C# - Reader rows

Question

I have a small problem with MySqlDataReader. I have data in MySql and I have column "name" and X rows under. Reader reads sucessfully all of this but output is in one string and looks like "FirtSecondThird" but i need all of this words in list word by word. The code is:

            while (reader.Read())
            {
                vystup.Add(reader[0].ToString());
            }
            connection.Close();
            string out1 = "";
            foreach (string outage in vystup)
            {
                out1 += outage + "\n";
            }
            return out1;

Does anyone know what to do with it? Thanks.

You can use [String.Join](https://learn.microsoft.com/en-us/dotnet/api/system.string.join?redirectedfrom=MSDN&view=net-6.0#System_String_Join_System_String_System_Collections_Generic_IEnumerable_System_String__) `string.Join(System.Environment.NewLine, vystup);` — styx, Apr 24 '22 at 07:24
Can you send me exactly where should i use string.Join(System.Environment.NewLine, vystup);? @StefanWuebbe maybe i am only stupid. Thanks — KvetinskyStepan, Apr 24 '22 at 07:56
@KvetinskyStepan instead of the `foreach` loop you can return the `string.join` result — styx, Apr 24 '22 at 07:57
`MySqlCommand command = new MySqlCommand(cmd, connection); MySqlDataReader reader = command.ExecuteReader(); while (reader.Read()) { out1 = reader.GetString("name"); vystup.Add(out1); } return string.Join(Environment.NewLine, vystup);` — KvetinskyStepan, Apr 24 '22 at 08:03
is it right? @StefanWuebbe // Sorry for format of the code.. — KvetinskyStepan, Apr 24 '22 at 08:04
Otherwise I'd also ask What's `vystup` content, type , where is it coming from? — Stefan Wuebbe, Apr 24 '22 at 08:16
@StefanWuebbe yes. It works! Thanks. I marked his answer as correct — KvetinskyStepan, Apr 24 '22 at 08:37
By the way your connection, command, and reader objects need to be disposed with `using` — Charlieface, Apr 24 '22 at 11:35
I can use `connection.Dispose(); command.Dispose(); reader.Dispose();` — KvetinskyStepan, Apr 24 '22 at 15:12
Yes but a `using` block ensures that `Dispose` is called even in the event of an exception. See eg https://stackoverflow.com/questions/212198/what-is-the-c-sharp-using-block-and-why-should-i-use-it — Charlieface, Apr 24 '22 at 16:19
I changed in all methods from `MySqlCommand command = new MySqlCommand(cmd, connection);` to `using MySqlCommand command = new MySqlCommand(cmd, connection);`. With reader i do same change and i added line `connection.Dispose();` @Charlieface — KvetinskyStepan, Apr 24 '22 at 16:24
You don't need `Dispose` or `Close` because `using` does that for you — Charlieface, Apr 24 '22 at 16:24

score 0 · Accepted Answer · answered Apr 24 '22 at 07:56

0

You can use String.Join

if vystup is a List<string> which contains the following items "first", "second","third"

then outputting string.join(Enviorment.NewLine, vystup) will yield

"first"

"second"

"third"

answered Apr 24 '22 at 07:56

styx

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SQL | C# - Reader rows

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