มีความคิดเห็นที่ไม่ถูกลบกี่ความคิดเห็น?ไม่จำเป็นต้องใช้ตารางทั้งหมด
How many undeleted comments are there?.It is not neccessary to use all the tables.
 PostHistory:  Id [ number]  PostHistoryTypeId [ number]  PostId [ number]  RevisionGUID [ other]  CreationDate [ time]  UserId [ number]  UserDisplayName [ text]  Comment [ text]  Text [ text]  ContentLicense [ text] 
SELECT COUNT(*) FROM Comments