how come Trigun isn't in our database but Trigun Maximum is....?

what chapter does the anime end at?? or the manga and the anime end the same?

With the help of a publisher friend, he submitted a Trigun story for the February 1995 issue of the Tokuma Shoten magazine Shōnen Captain, and began regular serialisation two months later in April.

However, Shōnen Captain was cancelled early in 1997, and when Nightow was approached by the magazine Young King Ours, published by Shōnen Gahōsha, they were interested in him beginning a new work. He was however troubled[1] by the idea of leaving Trigun incomplete, and requested to be allowed to finish the series. The publishers were sympathetic, and the manga resumed in 1998 as Trigun Maximum (トライガンマキシマム, Toraigan Makishimamu?). The story jumps forward two years with the start of Maximum, and takes on a slightly more serious tone, perhaps due to the switch from a shōnen to a seinen magazine. Despite this, Nightow has stated[2] that the new title was purely down to the change of publishers, and rather than being a sequel it should be seen as a continuation of the same series.

Shōnen Gahōsha later bought the rights to the original three volume manga series and reissued it as two enlarged volumes.