Where to store Connection String in Web.Config?

We can store Connection String in Web.config file in two ways

One is

<connectionStrings>
    <clear/>
    <add name="LocalSqlServer"
          connectionString="Data Source=(local);Initial Catalog=aspnetdb;Integrated Security=True"
          prov开发者_如何学GoiderName="System.Data.SqlClient" />
</connectionStrings>

Other One is

<appSettings>
     <add key="ConnectionString"
       value="server=localhost;database=Northwind;uid=sa;password=secret;" />
</appSettings>

Now I want to know

What is difference between these two approach?

Which one is better way?

What are their limitations?

UPDATE:Can you explain that <connectionString> has any significant advantage over <appSetting>?

The connectionStrings section is dedicated to connection strings and was only introduced in .NET 2.0.

appSettings is more general and is to be used for other application settings.

You should use the connectionStrings section, as it can also be encrypted separately from any other settings.

The first approach can be accessed directly by some data controls like SQLDataSource.

Using the connectionStrings element would be the most appropriate way to handle connection strings. The appSettings element is how connection strings used to be handled before .NET 2.0. You can use either approach but it is probably easier to work with multiple connection strings if you use the connectionString element. With multiple connection strings stored in appSettings you would have to parse each name (or value) to work out if it is a connection string before you could use it. This leads to maintenance issues. It's easier to just check if all of the connectionString items are present.

If you add your connection strings to the appSettings section, you need to manually retrieve them using the ConfigurationManager.AppSettings.Get(key) method.

By adding your connection strings instead to the connectionStrings element, .NET can automatically find these by name when you create your connection object.

connection-string section is declare the connection for system.I mean that you application know that you string is connectionString. If you will use appSettings for application it is just any string value.

Besides the benefits mentioned in the other answers, connectionStrings elements have a providerName attribute that appSettings elements do not. This is particularly useful if your data source is not SQL Server.