CREATE TABLE event (Event_ID NUMBER, Date CLOB, Venue CLOB, Name CLOB, Event_Attendance NUMBER)
CREATE TABLE news_report (journalist_ID NUMBER, Event_ID NUMBER, Work_Type CLOB)
CREATE TABLE journalist (journalist_ID NUMBER, Name CLOB, Nationality CLOB, Age CLOB, Years_working NUMBER)

Return me a pie chart to show the average experience working length of journalists working on different role type.
SELECT Work_Type, AVG(Years_working) FROM journalist AS t1 JOIN news_report AS t2 ON t1.journalist_ID = t2.journalist_ID GROUP BY t2.Work_Type
SELECT "Work_Type", AVG("Years_working") FROM "journalist" "t1" JOIN "news_report" "t2" ON "t1"."journalist_ID" = "t2"."journalist_ID" GROUP BY "t2"."Work_Type"