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（）

A.2
B.7
C.9
D.14

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?（）

A.SELECT UNIQUE dept FROM staff
B.SELECT DISTINCT dept FROM staff
C.SELECT (dept) UNIQUE FROM staff
D.SELECT (dept) DISTINCT FROM staff

单项选择题In which of the following situations should correlation names be used?（）

A.A table referenced in the FROM clause has no indexed column.
B.The table referenced in the FROM clause has more than 200 columns.
C.Two or more tables in the FROM clause have identical column names.
D.The FROM clause contains two or more tables in the SELECT statement.

单项选择题Consider the following table called EMPLOYEES: ID FIRSTNAME LASTNAME JOB LEVEL CLERK 3 If the following SQL statement is executed, how many rows will be deleted? DELETE FROM employees WHERE 1 = 1（）

A.0
B.1
C.3
D.6

单项选择题Which of the following is a feature of a unit of work?（）

A.It applies to a single data server.
B.It is a recoverable sequence of operations.
C.Its value can be queried from the system catalog tables.
D.It begins when the application connects to the data server.