How does one play a longer note interrupted by the same note in another voice?

Question

I found this note and I couldn't figure it out. How can I play D flat 3 beats when I got in the last beat another D flat? The last one interrupt the first one that why I cant play the first D flat All the three beats. If you have answer please let me know

Answer 1

Those are intended as two separated voices, and it's common for keyboard instruments (but not only) to have to play "again" a note that is theoretically still playing in another, and that's also for historical reasons: it was common to have a keyboard instrument with more than one keyboard.

Consider this excerpt from the second Praeludium of the first Well-Tempered Clavier book (note the C on the top staff):

That's to be intended more as musical coherence (that voice should play for the whole bar), than "key consistency".
Also, writing your example in a "correct" way would have made the score more cluttered, without any real benefit.

So, just play it again after releasing it as late as possible.