Database: art_1
Question: What are the first and last names of artists who have painted using both oil and lithographic mediums?
SQL:
SELECT T1.lname ,  T1.fname FROM artists AS T1 JOIN paintings AS T2 ON T1.artistID  =  T2.painterID WHERE T2.medium  =  "oil" INTERSECT SELECT T3.lname ,  T3.fname FROM artists AS T3 JOIN paintings AS T4 ON T3.artistID  =  T4.painterID WHERE T4.medium  =  "lithograph"