To achieve this requirement, you need to create a "connectionstring" to connect them. Here is a simple demo that read data to "DataGridView".
private void Form1_Load(object sender, EventArgs e)
{
    // builder connection string
    SqlConnectionStringBuilder builder = new SqlConnectionStringBuilder();
    // set server
    builder.DataSource = @"datasource name";
    // set database
    builder.InitialCatalog = @"catalog name";
    // access the database using the existing windows security certificate
    builder.IntegratedSecurity = true;
    //// if you want to use user id and password
    //// set user name
    //builder.UserID = "Kyle";
    //// set password
    //builder.Password = "123456";
    using (SqlConnection sqlconn = new SqlConnection(builder.ConnectionString))
    {
        SqlCommand sqlcomm = new SqlCommand("select * from Table_1", sqlconn);
        SqlDataAdapter sqlAdapter = new SqlDataAdapter(sqlcomm);
        DataSet ds = new DataSet();
        sqlAdapter.Fill(ds, "Table_1");
        dataGridView1.DataSource = ds.Tables["Table_1"];
    }
}
Properties in SQL Server:

Result:

原文:https://www.cnblogs.com/jizhiqiliao/p/10329986.html