How to Create a Connection File

Question

I am connecting to the database with the code below

     string connString = @"Data source = test2 ; Database=test1data ; User Id=a ; Password=test1234";
   using (SqlConnection sqlConn = new SqlConnection(connString))
            {
                string sqlQuery = @"SELECT * from Zone";
                SqlCommand cmd = new SqlCommand(sqlQuery, sqlConn);
                SqlDataAdapter da = new SqlDataAdapter(cmd);
                DataTable table = new DataTable();
                da.Fill(table);
                dataGridView1.DataSource = new BindingSource(table, null);
            }

But I wanted to create a file to connect that could be changed.

For example:

I'm connecting to a database, but changing this file I'll connect to another database

what do you mean by ***"that could be changed."***? You mean on the fly? — xGeo, Aug 16 '17 at 10:21
There're like thousand solutions. We cannot know which one you want. 1) storing connection string in a file with one line; 2) storing connection string if app.config; 3) storing connection string in xml file and so on. — KamikyIT, Aug 16 '17 at 10:24

score 0 · Accepted Answer · answered Aug 16 '17 at 10:25

0

Add a <connectionStrings> section to your App.config/Web.config file.

<configuration>
  <connectionStrings>
    <add name="{your connection name}" connectionString="{your connection string}" />
  </connectionStrings>
...
</configuration>

Read it using the ConfigurationManager

using System.Configuration;

var connectionString = 
    ConfigurationManager.ConnectionStrings["{your connection name}"].ConnectionString;

See ConfigurationManager.ConnectionStrings

answered Aug 16 '17 at 10:25

Georg Patscheider

9,357
1
26
36

That app.config is other file ? – Pedro Azevedo Aug 16 '17 at 10:31
`App.config` is the standard file to hold config values in .NET, it will be created automatically if you create a new project in Visual Studio. – Georg Patscheider Aug 16 '17 at 10:33
I am using this on app.config `` and it give me a error when I run the error is ConfigurationErrorsException: Connectionstrings Unknown configuration section. – Pedro Azevedo Aug 16 '17 at 12:51
Did you put the `` inside ``? – Georg Patscheider Aug 16 '17 at 14:06
yes I did , my code is this ` ` – Pedro Azevedo Aug 16 '17 at 14:54
`` is case sensitve (uppercase "S"); also make sure that you only have one `` section in the file. – Georg Patscheider Aug 16 '17 at 15:00
If your project is a library (instead of a console app), see here: https://stackoverflow.com/questions/1742929/net-app-config-in-library-project – Georg Patscheider Aug 16 '17 at 15:08
my project is a form – Pedro Azevedo Aug 16 '17 at 15:08
Then see here: https://stackoverflow.com/questions/114527/simplest-way-to-have-a-configuration-file-in-a-windows-forms-c-sharp-application – Georg Patscheider Aug 16 '17 at 15:10

How to Create a Connection File

For example:

1 Answers1