`DataTable` does not contain a definition for 'Fill' - c#

Question

I am not understanding why I am getting an error after reading documentation in regards to the .Fill() . Am I missing something that is causing this to return with an error?

    protected void FillData()
    {
        using (SqlConnection connection = new SqlConnection(@"Data Source = (LocalDB)\MSSQLLocalDB;AttachDbFilename= C:\Users\home\Documents\C# Programs\shop\Database.mdf ;Integrated Security = True"))
        {
            connection.Open();

            using (SqlDataAdapter dataAdapter = new SqlDataAdapter("select * from Employee", connection))
            {
                DataTable table = new DataTable();
                table.Fill(table);
                employeeDataGridView.DataSource = table;
            }

        }
    }

Answer 1

The problem is in this line of code

table.Fill(table);

You can't use table, to fill your table. The correct syntax would be

dataAdapter.Fill(table) 

Answer 2

You can't populate a DataTable in that way, you need to fill your DataAdapter, use a DataSet and then set the DataGridView to use this.

using (SqlDataAdapter dataAdapter = new SqlDataAdapter("select * from Employee", connection))
{
    var ds = new DataSet();
    dataAdapter.Fill(ds);
    employeeDataGridView.DataSource = ds.Tables[0];
}

Answer 3

The neatest way to code this up is:

protected void FillData()
{

        using (SqlDataAdapter dataAdapter = new SqlDataAdapter("select * from Employee", @"Data Source = (LocalDB)\MSSQLLocalDB;AttachDbFilename= C:\Users\home\Documents\C# Programs\shop\Database.mdf ;Integrated Security=True"))
        {
            DataTable table = new DataTable();
            dataAdapter.Fill(table);
            employeeDataGridView.DataSource = table;
        }


}

It'll get neater if you put your connection string in a static "global" variable somewhere

Points of note:

• use the dataadapter constructor that takes two strings - it will create the connection and the command for you
• you don't need to open the connection for the adapter- it knows how to
• this means you can have just one using
• if your sql needs parameters put them inside the using as dataAdapter.SelectCommand.Paramaters.Add...
• you could turn this into a method that accepts any sql string and parameter collection and returns you a datatable
• consider putting a WHERE clause in your sql; users might not like to see a grid with 20,000 employees in because it makes it harder to edit a handful of employees

It would be better to add a DataSet to your project (right click project, add>>new item, choose dataset - it gives you something that looks like a db visual design surface you can add queries to, create datatables that become components that can be added to your forms/create databound controls automatically) and create strongly typed datatables and table adapters

An alternative better route than this would be to use Dapper and strongly typed POCOs