Requête SQL pour compter les enregistrements par mois

Vous y étiez presque :ajoutez simplement l'utilisateur à la liste de sélection :

select [Usr],
  [1] AS January,
  [2] AS February,
  [3] AS March,
  [4] AS April,
  [5] AS May,
  [6] AS June,
  [7] AS July,
  [8] AS August,
  [9] AS September,
  [10] AS October,
  [11] AS November, 
  [12] AS December 
from
(
SELECT MONTH(DateVisit) AS month, [User], [User] as [Usr] FROM UserVisit
) AS t
PIVOT (
COUNT([User])
  FOR month IN([1], [2], [3], [4], [5],[6],[7],[8],[9],[10],[11],[12])
) p