Monday, September 9, 2019


1.Find the names and ages of all sailors.
SQL> select sname,age  from sailors ;
SNAME             AGE                                                                                                  
----------           ----------                                                                                                  
Dustin                 45.0                                                                                                  
Brutus                 33.0                                                                                                 
Lubber                55.5                                                                                                  
Andy                   25.5                                                                                                  
Rusty                  35.0                                                                                                  
Horatio               35.0                                                                                                  
Zorba                 16.0                                                                                                  
Horatio              35.0                                                                                                  
Art                     25.5                                                                                                  
Bob                   63.5                                                                                                  
10 rows selected.
2.Find all sailors with a rating above 7.
SQL> select * from sailors  where rating>7;
       SID SNAME          RATING        AGE                                                                            
       ------ ---------- ---------- ----------                                                                             
        31 Lubber              8       55.5                                                                            
        32 Andy                8       25.5                                                                             
        58 Rusty              10         35                                                                            
        71 Zorba              10         16                                                                             
        74 Horatio             9         35                                                                            
3.Find the names of sailors who have reserved boat number 103.
SQL> select * from sailors  s,reserves_18 r where s.sid=r.sid and r.bid=103;
       SID SNAME          RATING        AGE    BID    DAY                                                  
---------- ---------- ---------- ----------  -------- ------                                            
        22 Dustin              7         45     103   10-AUG-98                                            
        31 Lubber              8       55.5     103   11-JUN-98                                            
        74 Horatio             9         35     103   09-AUG-98                                            
4.Find the sids of sailors who have reserved a red boat.
SQL> select s.sid from sailors  s,reserves_18 r,boats_18 b
  2  where
  3  s.sid=r.sid and
  4  r.bid=b.bid and
  5  b.color='red';
       SID                                                                     
----------                                                                     
        22                                                                      
        22                                                                     
        31                                                                     
        31                                                                     
        64                                                                     
5.Find the names of sailors who have reserved a red boat.
SQL> select s.sname from
  2  sailors  s,reserves_18 r,boats_18 b
  3   where
  4  s.sid=r.sid and
  5   r.bid=b.bid and
  6   b.color='red';
SNAME                                                                          
----------                                                                     
Dustin                                                                          
Dustin                                                                         
Lubber                                                                         
Lubber                                                                         
Horatio                                                                        
6.Find the colors of boats reserved by Lubber.
SQL>select b.color from
  1   sailors  s,reserves_18 r,boats_18 b
  2   where
  3   s.sid=r.sid and
  4  r.bid=b.bid and
  5 s.sname='Lubber'
COLOR                                                                          
-----                                                                          
red                                                                            
green                                                                          
red                                                                            
7.Find the names of sailors who have reserved atleast one boat.
SQL> select s.sname from
       2  sailors  s,reserves_18 r,boats_18 b
       3  where
       4  s.sid=r.sid
       5  and r.bid=b.bid
       6  and s.sid in
       7 (select sid from reserves_18 group by sid having count(s.sid)>1)
SNAME                                                                          
----------                                                                     
Dustin                                                                         
Dustin                                                                          
Dustin                                                                         
Dustin                                                                         
Lubber                                                                          
Lubber                                                                         
Lubber                                                                         
Horatio                                                                         
Horatio                                                                        
9 rows selected.
8.Compute increments for the ratings of persons who have sailed two different boats on the same day.
SQL> select rating+1 from sailors  where
  2  sid in
  3  (select sid from reserves_18 group by sid
  4  having count(day)>+2);
  RATING+1                                                                     
----------                                                                      
         8                                                                     
         9                                                                     
9.Find the ages of sailors whose name begins and ends with B and has at least three characters.
SQL>select age from  sailors   s where s.sname like 'B_%b';
       AGE                                                                     
----------                                                                     
      63.5  
10.Find the names of sailors who have reserved a red or a green boat.
SQL>
  1  ( select s.sname from
  2   sailors   s  ,reserves_18 r,boats_18 b
  3   where  s.sid=r.sid and
  4   r.bid=b.bid and
  5  b.color='red')
  6  intersect
  7    (select s.sname from
  8    sailors   s  ,reserves_18 r,boats_18 b
  9    where  s.sid=r.sid and
  10    r.bid=b.bid and
  11  b.color='green')
SNAME                                                                          
----------                                                                      
Dustin                                                                         
Horatio                                                                        
Lubber
11.Find the names of sailors who have reserved aboth a red and a green boat.
SQL>select s.sname
       2 from sailors  s
       3 where s.sid in((select r.sid from boats18 b,reserves_18 r
       4 where r.bid=b.bid and b.color='red')
       5 UNION
       6 (select r2.sid
       7 from boats_18 b2,reserves_18 r2
       8 where r2.bid=b2.bid and b2.color='green'));
SNAME                                                                          
----------                                                                     
Dustin                                                                                                                                                  
Lubber                                                                                                                                                                                                                      
12.Find the sids of all sailors who have reserved red boats but not green boats.
SQL>  select s.sid  from  sailors   s  ,reserves_18 r,boats_18 b
  2   where
  3   s.sid=r.sid
  4  and
  5   r.bid=b.bid and b.color='red'
  6  and
  7  b.color!='green';
       SID                                                                     
----------                                                                      
        22                                                                     
        22                                                                     
        31                                                                      
        31                                                                     
        64                                                                     
13.Find all sids of sailors who have amrating of 10 or have reserved boat 104
SQL>(select s.sid  from  sailors   s  ,reserves_18 r,boats_18 b
   1   where
   2   s.sid=r.sid
   3  and
   4  s.rating=10)
   5  union
   6  (select s.sid from sailors   s  ,reserves_18 r,boats_18 b
   7  where
   8   s.sid=r.sid
9 and r.bid=104);
       SID                                                                     
----------                                                                     
        22                                                                     
        31                                                                      
14.Find the names of sailors who have not reserved a red boat.
SQL> select s.sid  from sailors   s  ,reserves_18 r,boats_18 b
  2  where
  3    s.sid=r.sid
  4   and
  5  r.bid=b.bid
  6  and
  7  b.color!='red';
       SID                                                                     
----------                                                                     
        22                                                                      
        22                                                                     
        31                                                                     
        64                                                                     
        74                                                                    
15.Find sailors whose rating is better than some sailor called Horatio.
SQL> select * from sailors  where rating > all
  2  (select rating from sailors  where sname='Horatio');
       SID SNAME          RATING        AGE                                    
---------- ---------- ---------- ----------                                    
        58 Rusty              10         35                                    
        71 Zorba              10         16                                    
16.Find sailors whose rating is better than every sailor called Horatio.
SQL>
  1  select * from sailors  where rating > any
  2 (select rating from sailors  where sname='Horatio');
       SID SNAME          RATING        AGE                                    
---------- ---------- ---------- ----------                                    
        31 Lubber              8       55.5                                    
        32 Andy                8       25.5                                    
        58 Rusty              10         35                                    
        71 Zorba              10         16                                    
        74 Horatio             9         35                                    
17.Find the sailors with the highest rating.
SQL> select sname from sailors  where rating=(select max(rating) from  sailors  );
SNAME                                                                           
----------                                                                     
Rusty                                                                          
Zorba 
18.Find the names of sailors who have reserved aboth a red and a green boat.
SQL>select s.sname
       2 from sailors  s
       3 where s.sid in((select r.sid from boats18 b,reserves_18 r
       4 where r.bid=b.bid and b.color='red')
       5 UNION
       6 (select r2.sid
       7 from boats_18 b2,reserves_18 r2
       8 where r2.bid=b2.bid and b2.color='green'));
SNAME                                                                          
----------                                                                     
Dustin                                                                                                                                                   
Lubber                                                                                                                                                                                                                      
19.Find the names of sailors who have reserved all boats.
SQL> select * from sailors   where
  2  not exists
  3  (( select bid from boats_18)
  4  minus
  5  (select bid from sailors  s,reserves_18 r
  6  where s.sid=r.sid));
       SID SNAME          RATING        AGE                                    
---------- ---------- ---------- ----------                                    
        22 Dustin              7         45                                    
        29 Brutus              1         33                                    
        31 Lubber              8       55.5                                    
        32 Andy                8       25.5                                    
        58 Rusty              10         35                                    
        64 Horatio             7         35                                    
        71 Zorba              10         16                                     
        74 Horatio             9         35                                    
        85 Art                 3       25.5                                    
        95 Bob                 3       63.5                                     
10 rows selected.
20.Find the average age of all sailors.
SQL> select avg(age) from sailors ;
  AVG(AGE)                                                                     
----------                                                                      
      36.9                                                                     
21.Find the average of sailors with a rating of 10.
SQL> select avg(age) from sailors  where rating=10;
  AVG(AGE)                                                                      
----------                                                                     
      25.5                                                                     
22.Find the name and age of oldest sailor.
SQL> select sname , age from sailors
  1 where age=(select max(age) from sailors )
SNAME             AGE                                                          
---------- ----------                                                          
Bob              63.5                                                          
23.Count the number of sailors.
SQL> select count(sid) from sailors ;
COUNT(SID)                                                                     
----------                                                                      
        10                                                                     
24.Count the number of different sailor names.
SQL> select distinct count(distinct(sname)) from sailors ;
COUNT(DISTNCT(SNAME))                                                                      
----------                                                                   
        9 
25.Find the names of sailors who are older than the oldest sailor with a rating of 10.
select * from sailors
 where age>all
(select age from sailors
where rating=10
);
SID   SNAME      RATING     AGE
-----   -----------      -------------     --------
22     dustin        7                 45
31     lubber       8                 55.5
95     bob            3                 63.5
26.Find the age of the youngest sailor for each rating level.
SQL> select rating,min(age) from sailors  group by rating
    RATING   MIN(AGE)                                                          
---------- ----------                                                          
         1         33                                                          
         3       25.5                                                          
         7         35                                                          
         8       25.5                                                          
         9         35                                                          
        10         16                                                          
6 rows selected.
27.Find the age of the youngest sailor who is eligible to vote (i.e., is atleast 18 years old) for each rating level with atleast two such sailors.
SQL>select min(age) from sailors  where age>=18
group by rating having count(age)>1;
MIN(AGE)
________________
25.5
35
25.5
28.For each red boat, find the number of reservations for this boat.
SQL> select count(r.sid) from reserves_18 r,boats_18 b
where r.bid=b.bid and b.color='red'group by b.bid;
COUNT(R.SID)
___________________
3
2
29. Find the average age of sailors for each rating level that has atleast two sailors.
SQL> select avg(age),rating,count(sid) from sailors
       2  group by rating
       3  having count(sid)>=2;
  AVG(AGE)     RATING COUNT(SID)                                               
    ----------           ----------        ----------                                               
          44.5                   3          2                                               
            40                    7          2                                                
         40.5                    8          2                                               
         25.5                  10          2                                               
30.Find the average age of sailors who are of voting age (i.e., is atleast 18 years old) for each rating level that has atleast two sailors.
SQL> select avg(age) from sailors
group by rating
having count(sid)>1;
AVG(AGE)
_______________
40.5
40
44.5
25.5
31.Find the average age of sailors who are of voting age (i.e., is atleast 18 years old) for each rating level that has atleast two such sailors.
SQL> select min(age) from sailors  where age>=18
group by rating having count(age)>1;
MIN(AGE)
________________
25.5
35
25.5
32. Find those ratings for which the average age of sailors is the minimum over all ratings.
SQL> select rating
  2    from (select  avg(age) age,rating from sailors
  3                       group by  rating)
  4        where age=(select min(avg(age)) from sailors
  5                         group by rating);
    RATING                                                                     
----------                                                                     
        10                                              




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