Introduction to SQL Each index consumes extra storage space and also requires overhead maintenance time whenever indexed data change value. False True False True 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? 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 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 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 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 COUNT(r1.bid) > r2.bid ANSWER DOWNLOAD EXAMIANS APP
Introduction to SQL COUNT(field_name) tallies only those rows that contain a value; it ignores all null values. False True False True ANSWER DOWNLOAD EXAMIANS APP
Introduction to SQL Which of the following SQL commands is used to retrieve data? SELECT DELETE INSERT JOIN SELECT DELETE INSERT JOIN ANSWER DOWNLOAD EXAMIANS APP
Introduction to SQL DISTINCT and its counterpart, ALL, can be used more than once in a SELECT statement. True False True False ANSWER DOWNLOAD EXAMIANS APP
Introduction to SQL To sort the results of a query use: GROUP BY. None of these ORDER BY. SORT BY. GROUP BY. None of these ORDER BY. SORT BY. ANSWER DOWNLOAD EXAMIANS APP
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