Table: destroyer_1943
Columns: name
pennant
builder
laid_down
launched
commissioned
fate

Question: What are the commissioned for scotts, greenock and chieftain?
SQL: SELECT "commissioned" FROM destroyer_1943 WHERE "builder" = 'Scotts, Greenock' AND "name" = 'Chieftain'

Question: What is the builder launched 30 october 1944?
SQL: SELECT "builder" FROM destroyer_1943 WHERE "launched" = '30 October 1944'