Introduction to SQL Which of the following group functions ignore NULL values? MAX SUM All of these COUNT MAX SUM All of these COUNT ANSWER DOWNLOAD EXAMIANS APP
Introduction to SQL What operator tests column for the absence of data? NOT operator IS NULL operator None of these EXISTS operator NOT operator IS NULL operator None of these EXISTS operator ANSWER DOWNLOAD EXAMIANS APP
Introduction to SQL Which of the following query finds the name of the sailors who have reserved at least two boats? All of these SELECT DISTINCT s.sname FROM sailors s, reserves r1, reserves r2 WHERE s.sid = r1.sid AND r1.sid = r2.sid AND r1.bid <> r2.bid SELECT DISTINCT s.sname FROM sailors s, reserves r1, reserves r2 WHERE s.sid = r1.sid AND COUNT(r1.bid) > r2.bid SELECT DISTINCT s.sname FROM sailors s, reserves r1, reserves r2 WHERE s.sid = r1.sid AND r1.sid = r2.sid AND r1.bid ≠ r2.bid All of these SELECT DISTINCT s.sname FROM sailors s, reserves r1, reserves r2 WHERE s.sid = r1.sid AND r1.sid = r2.sid AND r1.bid <> r2.bid SELECT DISTINCT s.sname FROM sailors s, reserves r1, reserves r2 WHERE s.sid = r1.sid AND COUNT(r1.bid) > r2.bid SELECT DISTINCT s.sname FROM sailors s, reserves r1, reserves r2 WHERE s.sid = r1.sid AND r1.sid = r2.sid AND r1.bid ≠ r2.bid ANSWER DOWNLOAD EXAMIANS APP
Introduction to SQL If you are going to use a combination of three or more AND and OR conditions, it is often easier to use the NOT and NOT IN operators. True False True False ANSWER DOWNLOAD EXAMIANS APP
Introduction to SQL The SELECT command, with its various clauses, allows users to query the data contained in the tables and ask many different questions or ad hoc queries. False True False True ANSWER DOWNLOAD EXAMIANS APP
Introduction to SQL Find the names of the countries whose condition is sunny. SELECT country FROM location WHERE city UNION (SELECT city FROM weather WHERE condition = 'sunny'); SELECT country FROM location WHERE condition = 'sunny'; SELECT country FROM location WHERE city IN (SELECT city FROM weather WHERE condition = sunny'); SELECT country FROM location WHERE city NOT IN (SELECT city FROM weather WHERE condition = 'sunny'); SELECT country FROM location WHERE city UNION (SELECT city FROM weather WHERE condition = 'sunny'); SELECT country FROM location WHERE condition = 'sunny'; SELECT country FROM location WHERE city IN (SELECT city FROM weather WHERE condition = sunny'); SELECT country FROM location WHERE city NOT IN (SELECT city FROM weather WHERE condition = 'sunny'); ANSWER DOWNLOAD EXAMIANS APP
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