How do I connect to a SQL database from C#?

Question

I am trying to write a local program management and install system for my home network, and I think I've got the technologies nailed down:

• C#/.NET/WPF for the client
• Lua for installation scripting support (through LuaInterface)
• SQL Server Express for maintaining a database of programs

However I'm unsure what specifically I'll use to connect C# to the database. Is there something built into the .NET framework for this? Bonus points if you have a suggestion on what I should use for interacting with said database.

Answer 1

Check out

• Introduction to ADO.NET Tutorial
• ADO.NET Tutorial Lesson 1
• An introduction to ADO.NET

I'm sure there's plenty more out there - just google for "ADO.NET" and "Tutorial" ......

UPDATE:

If you want to connect to your local SQL Server Express, and connect to the "Northwind" database, and read the top 5 customers from the "Customers" table, you'd have to do something like this:

string connectionString = "server=(local)\SQLExpress;database=Northwind;integrated Security=SSPI;";

using(SqlConnection _con = new SqlConnection(connectionString))
{
   string queryStatement = "SELECT TOP 5 * FROM dbo.Customers ORDER BY CustomerID";

   using(SqlCommand _cmd = new SqlCommand(queryStatement, _con))
   {
      DataTable customerTable = new DataTable("Top5Customers");
      
      SqlDataAdapter _dap = new SqlDataAdapter(_cmd);

      _con.Open();
      _dap.Fill(customerTable);
      _con.Close();

   }
}

Now you would have all 5 top customers from your Northwind database in the DataTable and you can inspect them, print them out, manipulate them - whatever you want to do.

That's ADO.NET in action!

As for the details of the connection string - what options you can use and what it should look like, check out the Connection Strings web site - it has tons of examples and explanations.