Question

For my database I create a new query and wrote

select * from dbname

using SQL Server Management Studio Express 2005. Saved it by name SQLQuery1.sql on the desktop.

Now I would like to call this query from C# code when an ASP.NET button is clicked and display the results in a gridview.

How do I call the query? Can I tell Visual Studio 2008 to please execute the query stored in ‘sqlquery1.sql’ ?

Where do I store the results so that I can bind them the display controls like a gridview, or traverse the data?

This is a website in C#, ASP.NET, Visual Studio 2008, and database is on the same computer using SQL Server 2005 Express

Answer 1

You cannot just execute a SQL script you stored on your computer’s desktop from an ASP.NET website.

You can either:

• turn your query into a stored procedure in SQL Server, something like:

  CREATE PROCEDURE dbo.proc_MyQuery
  AS
     SELECT (list of columns) 
     FROM dbo.MyTable
     WHERE (condition)
  

  When you do this, you can create a SqlCommand in your C# code and call that stored procedure and retrieve the results back.

or:

• you can execute the query directly from your C# code by creating a SqlConnection and a SqlCommand object and running that SQL statement.

These are both absolutely basic ADO.NET features – you should find tons of learning resources online for this.

For instance:

• ADO.NET 101 – Data Access with ADO.NET
• ADO.NET 101: SQL Connection
• ADO.NET 101: SqlCommand / Your guide to using this ADO.NET object to execute SQL Server commands
• Using ADO.NET for beginners
• ADO.NET for Beginners – Part 1

Which ever way you go, you basically need to have a SqlConnection to your database, and then a SqlCommand to execute the query. If you want to store the data so you can both bind it to a Gridview as well as navigate it in code, you probably want to store it in a DataTable. So your code would look something like this:

DataTable resultTable = new DataTable();

using(SqlConnection con = new SqlConnection("your connection string here"))
{
    string sqlStmt = "SELECT (columns) FROM dbo.YourTable WHERE (condition)";

    using(SqlCommand cmd = new SqlCommand(sqlStmt, con))
    {
        SqlDataAdapter dap = new SqlDataAdapter(cmd);
        dap.Fill(resultTable);
    }
}

and then to bind to the gridview, you’d use something like:

myGridView.DataSource = resultTable;
myGridView.DataBind();

and to navigate the DataTable, you can step through its .Rows() collection of data rows.