I've watched like maybe 3 episodes of SG-1. It has that one guy who likes to make bombs out of dental floss and Bisquick.

Wiki: Colonel Jack O'Neill, USAF was married and had one son, Tyler. But after a tragic accident when Tyler shot himself with O'Neill's personal gun (a Beretta 92 series pistol), O'Neill went to pieces, retired from his position and didn't talk to anyone.

When the Stargate was deciphered by Daniel Jackson, General West knew that O'Neill was suicidal and therefore perfect for the mission (in which he would go through with a team and detonate a nuclear warhead near the Stargate if there was any sign of danger), and had him reactivated.

On Abydos, O'Neill and the team found the indigenous population to be simple desert-dwellers. He made friends with a boy called Skaara, the son of the ambassador, (Kasuf) to the evil ruler, Ra (in Stargate SG-1, developed as a Goa'uld System Lord who was responsible for the enslavement of millions of people over the galaxy, as most System Lords are).

During the battle of Abydos, O'Neill fought in hand-to-hand combat against Ra's First Prime to regain control of the warhead (which has fallen into Goa'uld hands). As the motion picture played out, Ra attempted to escape, only to have O'Neill and Jackson transport the bomb to his ship, destroying it in orbit. O'Neill returned to Earth with all but Jackson (who has been married to a local woman, Sha'uri), and lied that the Abydos gate had been destroyed.

In the movie, Jack's son is named Tyler (the name is seen on an award in his room in an early scene.) as opposed to Charlie (as in the SG-1 series) or Jack Jr. (as in the non-SG-1 books.) Also, the Colonel's name in the film is O'Neil (with one L), a fact which was referenced lightheartedly in the TV series.