Store Zip file in Database

Try something like this:

using System.IO;

// ..

string filePath =  @"C:\Test\test.zip"; // or whatever

using (SqlConnection conn = new SqlConnection("connection string"))
{
    using (SqlCommand cmd = new SqlCommand())
    {
        byte[] bytes = File.ReadAllBytes(filePath);
        cmd.CommandText = @"INSERT INTO SomeTable(id, [file]) VALUES (@id, @file)";
        cmd.Parameters.AddWithValue("@id", someId); // some way of identifying file
        cmd.Parameters.AddWithValue("@file", bytes);
        cmd.Connection = conn;
        conn.Open();
        try
        {
            cmd.ExecuteNonQuery();
        }
        catch (Exception ex)
        {
             MessageBox.Show(ex.Message);
        }
    }
}