ตารางนี้มีโรงเรียนจำนวนเท่าใด ?ไม่จำเป็นต้องใช้ตารางทั้งหมด
what 's the number of schools represented in the table ?It is not neccessary to use all the tables.
 table_203_721:  id [ number]  "school" [ text]  "location" [ text]  "control" [ text]  "type" [ text]  "enrollment" [ number]  "founded" [ number] 
SELECT COUNT("school") FROM table_203_721