单项选择题
A.SELECT * FROM T1 MINUS SELECT * FROM T2
B.SELECT * FROM T1 EXCEPT SELECT * FROM T2
C.SELECT * FROM T2 UNION EXCEPT SELECT * FROM T1
D.SELECT * FROM T1 NOT EXISTS SELECT * FROM T2
单项选择题 How should the following UDF be invoked in order to convert US currency values stored in the EXPENSES table into Canadian currency?CREATE FUNCTION getratews11 ( country1 VARCHAR(100), country2 VARCHAR(100) ) RETURNS DOUBLE LANGUAGE SQL CONTAINS SQL EXTERNAL ACTION NOT DETERMINISTIC BEGIN ... END（）
单项选择题 Given the following tables: CONTINENTS ID NAME COUNTRIES 1 Antarctica 0 2 Africa 53 3 Asia 47 4 Australia 14 5 Europe 43 6 North America 23 7 South America 12 REGION ID LOCATION 1 East 2 West How many rows would be returned using the following statement? SELECT location FROM continents, region（）
单项选择题 Which of the following statements eliminates all but one of each set of duplicate rows in the DEPT column in the STAFF table?（）