CREATE TABLE market (Market_ID NUMBER, District CLOB, Num_of_employees NUMBER, Num_of_shops FLOAT, Ranking NUMBER)
CREATE TABLE phone_market (Market_ID NUMBER, Phone_ID CLOB, Num_of_stock NUMBER)
CREATE TABLE phone (Name CLOB, Phone_ID NUMBER, Memory_in_G NUMBER, Carrier CLOB, Price FLOAT)

For each phone, show its names and total number of stocks. Visualize by bar chart.
SELECT Name, SUM(T1.Num_of_stock) FROM phone_market AS T1 JOIN phone AS T2 ON T1.Phone_ID = T2.Phone_ID GROUP BY T2.Name
SELECT "Name", SUM("T1"."Num_of_stock") FROM "phone_market" "T1" JOIN "phone" "T2" ON "T1"."Phone_ID" = "T2"."Phone_ID" GROUP BY "T2"."Name"