Introduction to SQL Each index consumes extra storage space and also requires overhead maintenance time whenever indexed data change value. True False True False 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 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 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 Let the statementSELECT column1 FROM myTable;return 10 rows. The statementSELECT ALL column1 FROM myTable;will return exactly 10 rows None of these less than 10 rows more than 10 rows exactly 10 rows None of these less than 10 rows more than 10 rows ANSWER DOWNLOAD EXAMIANS APP
Introduction to SQL What does the following query find?(SELECT DISTINCT r.sidFROM boats b, reserves rWHERE b.bid = r.bidAND b.color = 'red')MINUS(SELECT DISTINCT r.sidFROM boats b, reserves rWHERE b.bid = r.bidAND b.color = 'green') Find the sailor Ids of atmost one sailor who have reserved red boats but not green boats None of These Find the sailor IDs of at least one sailor who have reserved red boats but not green boats Find the sailor IDs of all sailors who have reserved red boats but not green boats Find the sailor Ids of atmost one sailor who have reserved red boats but not green boats None of These Find the sailor IDs of at least one sailor who have reserved red boats but not green boats Find the sailor IDs of all sailors who have reserved red boats but not green boats ANSWER DOWNLOAD EXAMIANS APP
Introduction to SQL In an SQL SELECT statement querying a single table, according to the SQL-92 standard the asterisk (*) means that: all records meeting the full criteria are to be returned. None of these all columns of the table are to be returned. all records with even partial criteria met are to be returned. all records meeting the full criteria are to be returned. None of these all columns of the table are to be returned. all records with even partial criteria met are to be returned. ANSWER DOWNLOAD EXAMIANS APP
Introduction to SQL Which of the following do you need to consider when you make a table in SQL? Default values Primary keys All of these Data types Default values Primary keys All of these Data types ANSWER DOWNLOAD EXAMIANS APP
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