49135

MySQL select result save into c# variable

Question:

Can you please check my code and answer me how can i save a mysql select result into a c# string?

try { MySqlDataReader reader = null; string selectCmd = "SELECT * FROM TabelaUtilizatori"; MySqlCommand cmd = new MySqlCommand(selectCmd, _dbConnect.getConnection()); string result = cmd.ExecuteScalar().ToString(); label2.Text = result; } catch (Exception ex) { MessageBox.Show(ex.Message); }

or maybe this way?

using (_dbConnect.getConnection()) { MySqlCommand command = new MySqlCommand( "SELECT NAME FROM TABELAUTILIZATORI WHERE EMAIL = 'asdjaa@asdka.com'" _dbConnect.getConnection()); MySqlDataReader reader = command.ExecuteReader(); while (reader.Read()) { label2.Text= } reader.Close(); }

thanks a lot !

Answer1:

Yes,You can use ExecuteReader() for this..

try { MySqlDataReader reader = null; string selectCmd = "SELECT * FROM TabelaUtilizatori"; MySqlCommand command = new MySqlCommand(selectCmd, _dbConnect.getConnection()); reader = command.ExecuteReader(); while (reader.Read()) { string ColumnName = (string)reader["ColumnName"]; } } catch (Exception ex) { MessageBox.Show(ex.Message); }

Answer2:

You have to use a different api. ExecuteReader is more appropriate here and it will allow you to iterate through all results. An example can be found here :

<a href="https://msdn.microsoft.com/en-us/library/haa3afyz%28v=vs.110%29.aspx" rel="nofollow">https://msdn.microsoft.com/en-us/library/haa3afyz%28v=vs.110%29.aspx</a>

Note that there is no single result with this, there are multiple columns and multiple records, so these don't fit in a single string. Unless you want something like select count(*)

Also note that it is not considered good practice to have code like this select * from ... it is better to specify which columns you really need. Your application will be less likely to break if the datamodel changes.

Also read about using parameters in a query :

<a href="http://www.csharp-station.com/Tutorial/AdoDotNet/lesson06" rel="nofollow">http://www.csharp-station.com/Tutorial/AdoDotNet/lesson06</a>

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