Database: college_completion
Question: Give the total number of all graduated students from a 2-year public schools in Alabama in 2011.
SQL: SELECT SUM(T2.grad_cohort) FROM state_sector_details AS T1 INNER JOIN state_sector_grads AS T2 ON T2.stateid = T1.stateid WHERE T1.state = 'Alabama' AND T2.year = 2011 AND T1.level = '2-year' AND T1.control = 'Public' AND T2.race = 'X'