How many pieces did Johann Sebastian Bach compose??????????????

According to the 1990 edition of Wolfgang Schmieder's authoritative Thematisch-systematisches Verzeichnis der Musikalischen Werke von Johann Sebastian Bach, Bach-Werke-Verzeichnes (BWV), there are 1120 works plus various bits and pieces, fragments, misattributions, etc., listed in the Anhangs at the end of the book. Occasionally a new manuscript comes to light, but you're pretty safe if you say about 1120.

wiki says that he had over 1000

Much of Bach's music was lost because the only manuscripts were used to wrap fish, and were ruined. Such a shame.

1120