title: sql returning no rows selected
body: <p>how can I make this sql query return zero for the count function instead of no rows selected?</p>
  
  <pre><code>select ur.uno, count(*)*5
  from userresponse ur, question q
  where ur.eno = q.eno 
    and q.correctanswer = ur.response 
    and q.qno = ur.qno 
    and ur.uno = '1' 
    and q.eno = '1'
  group by ur.uno
  </code></pre>
  
  <p>q.correctanswer = ur.response is never true for this query that's what causes the no row selected, however I want to return zero.</p>
  
  <p>sample data</p>
  
  <p>Note:
  - "||" is used to concatenate strings
  - each string is between a pair of single quotes.
  - each record is between "(" and ")".
  - fields are ordered according to fields in tables
  - "\n" means a new line</p>
  
  <blockquote>
    <p>======exams data==========</p>
    
    <p>(1,'Java Programming',60,1)</p>
    
    <p>(3,'Elementary History',10,3)</p>
    
    <p>======questions data=========== </p>
    
    <p>(1,1,'Choose the operations that can be performed on String
    objects:(A) +\n(B) + =\n(C) -\n(D) %\n(E) ^','B')</p>
    
    <p>(1,2,'What will be the result of the expression\na % b\nwhen a and b
    are of type int and their values are a = -17 and b = -6?','A')</p>
    
    <p>(1,3,'What will be the result of the expression\na % b\nwhen a and b
    are of type int and their values are a = 10 and b = 6?','B')</p>
    
    <p>(1,4,'Consider the following code:\nint x, y, z\ny = 1\nz = 5\nx = 0
    - (++y) + z++\nAfter execution of this, what will be the values of x, y and z?','C')</p>
    
    <p>(1,5,'Identify the statements that are correct:\n(A) int a = 13,
    a>>2 = 3\n(B) int b = -8, b>>1 = -4\n(C) int a = 13, a>>>2 = 3\n(D)
    int b = -8, b>>>1 = -4','E')</p>
    
    <p>(1,6,'If not assigned a value, a variable of type char has the
    following default value:','A')</p>
    
    <p>(1,7,'What will be the value of a after execution of the following
    statements:\nint a = 23, b = 34\na = ((a &lt; b) ? (b + a) : (b -
    a)','B')</p>
    
    <p>(1,8,'Which of the following is not a hexadecimal number?\n(A)
    999\n(B) (hex)23\n(C) 0x556\n(D) 0x1F2','C')</p>
    
    <p>(1,9,'if(check4Biz(storeNum) != null) {}\nReferring to the above,
    what datatype could be returned by method check4Biz()?','D')</p>
    
    <p>(1,10,'Select the invalid assignment statements from the
    following:\n(A) float x = 238.88\n(B) double y = 0x443\n(C) int n =
    (int) true\n(D) long m =778645','A')</p>
    
    <p>(1,11,'int j\nfor(int i=0i&lt;14i++) {\nif(i&lt;10) {\nj = 2 +
    i\n}\nSystem.out.println("j: " + j + " i: " + i)\n}\nWhat is WRONG
    with the above code?','E')</p>
    
    <p>(1,12,'Consider the following code:\nclass ClassA\n{\npublic static
    void main(String args [ ])\n{\nClassB b = classB()\n}\nClassA(int x) {
    }\n}\nclass ClassB extends ClassA\n{\n}\nWhat will happen when we
    compile and run this code?','A')</p>
    
    <p>(1,13,'The keywords reserved but not used in the initial version of
    Java are:\n(A) union\n(B) const\n(C) inner\n(D) goto\n(E) boolean\n(F)
    synchronized','C')</p>
    
    <p>(1,14,'We would like to make a member of a class visible in all
    subclasses regardless of what package they are in. Which one of the
    following keywords would achieve this?','D')</p>
    
    <p>(1,15,'Which of the following are not keywords?\n(A) NULL\n(B)
    implements\n(C) protected\n(D) extended\n(E) string','B')</p>
    
    <p>(3,1,'The Battle of Gettysburg was fought during which war?','C') </p>
    
    <p>(3,2,'Neil Armstrong and Buzz Aldrin walked how many \n' ||
           'minutes on the moon in 1696?','B')  </p>
    
    <p>(3,3,'Which Presidents held office during World War II?','D')  </p>
    
    <p>(3,4,'In a communist economic system, people:','B')  </p>
    
    <p>(3,5,'Which president did not die while in office?','D') </p>
    
    <p>(3,6,'Which state refused to attend the Constitutional Convention
    \n' ||
           'in 1787 because it didn''t want the United States government \n' ||
           'to interfere with already established state affairs?','A') </p>
    
    <p>(3,7,'Who founded Buddhism?','A')  </p>
    
    <p>(3,8,'Where is India?','D')</p>
    
    <p>(3,9,'What is the dominant religion in India?','B') </p>
    
    <p>(3,10,'Near which river did archaeologists find India''s \n' ||
            'first civilization?','B') </p>
    
    <p>========== answerOption data ============</p>
    
    <p>(3,8,'A','Australia')  (3,8,'B','America')  (3,8,'C','Africa') 
    (3,8,'D','Asia')  (3,1,'A','World War II')  (3,1,'B','The
    Revolutionary War') (3,1,'C','The Civil War') (3,1,'D','World War I')
    (3,2,'A','123')  (3,2,'B','None')  (3,2,'C','10')  (3,2,'D','51') 
    (3,3,'A','Franklin D. Roosevelt')  (3,3,'B','Dwight D. Eisenhower') 
    (3,3,'C','Harry Truman')  (3,3,'D','Both A and C')  (3,4,'A','Are
    forced to work as slaves')  (3,4,'B','Work for the common good') 
    (3,4,'C','Work from home computers')  (3,4,'D','Don''t work')<br>
    (3,5,'A','John F. Kennedy')  (3,5,'B','Franklin D. Roosevelt') 
    (3,5,'C','Abraham Lincoln')  (3,5,'D','Ronald Reagan') 
    (3,5,'E','James A. Garfield')  (3,7,'A','Siddharta Gautama') 
    (3,7,'B','Jesus Christ')  (3,7,'C','Mahatma Gandhi') 
    (3,7,'D','Muhammad')  (3,6,'A','Rhode Island')  (3,6,'B','New
    Hampshire')  (3,6,'C','New Jersey')  (3,6,'D','New York') 
    (3,9,'A','Islam')  (3,9,'B','Hinduism')  (3,9,'C','Christianity') 
    (3,9,'D','Buddhism')   (3,10,'A','The Tiber River')  (3,10,'B','The
    Indus River')  (3,10,'C','The Yellow River')  (3,10,'D','The Nile
    River') (1,1,'A','(D) &amp; (E)') (1,1,'B',' (A) &amp; (B)') (1,1,'C','(D)')
    (1,1,'D','(A)') (1,1,'E','None of these') (1,2,'A','-17')
    (1,2,'B','5') (1,2,'C','3') (1,2,'D','-5') (1,2,'E','None of these')
    (1,3,'A','1.66') (1,3,'B','4') (1,3,'C','2') (1,3,'D','1')
    (1,3,'E','None of these') (1,4,'A','x = 4, y = 1, z = 5') (1,4,'B',' x
    = -7, y = 1, z = 5') (1,4,'C','x = 3, y = 2, z = 6') (1,4,'D',' x = 4, y = 2, z = 6') (1,4,'E',' x = 8, y = 2, z = 1') (1,5,'A','(C) &amp; (D) ')
    (1,5,'B',' (A), (B) &amp; (C) ') (1,5,'C','(A), (B), (C) &amp; (D)')
    (1,5,'D','(A) &amp; (B) ') (1,5,'E','None of the above')
    (1,6,'A','\uffff') (1,6,'B','\u0000') (1,6,'C','" " (space)')
    (1,6,'D','\u0001') (1,6,'E','None of the above') (1,7,'A','23')
    (1,7,'B','Error. Cannot be executed.') (1,7,'C','57') (1,7,'D','11')
    (1,7,'E','34') (1,8,'A','(A), (B) &amp; (C)') (1,8,'B','(C)')
    (1,8,'C','(A) &amp; (B) ') (1,8,'D','(A)') (1,8,'E','(D)')
    (1,9,'A','Boolean') (1,9,'B','Int') (1,9,'C','String')
    (1,9,'D','Char') (1,9,'E','Byte') (1,10,'A','(A) &amp; (C)')
    (1,10,'B','(A) &amp; (B)') (1,10,'C','(B) ') (1,10,'D','(B) &amp; (D) ')
    (1,10,'E','(D)') (1,11,'A','Integer "j" is not initialized.')
    (1,11,'B','Nothing.') (1,11,'C','You cannot declare integer i inside
    the for-loop declaration.') (1,11,'D','The syntax of the "if"
    statement is incorrect.') (1,11,'E','You cannot print integer values
    without converting them to strings.') (1,12,'A','Will compile and run
    successfully ') (1,12,'B','Error. ClassA does not define a no-argument
    constructor ') (1,12,'C','Error. There is no code in the constructor
    ClassA(int x) ') (1,12,'D','Error. ClassB does not define a
    no-argument constructor ') (1,12,'E','Error. There is no code in the
    class ClassB ') (1,13,'A','(C) &amp; (E) ') (1,13,'B','(B),(C) &amp; (D)')
    (1,13,'C','(A), (C) &amp; (E)') (1,13,'D','All of these. ')
    (1,13,'E','None of these. ') (1,14,'A','private ') (1,14,'B','public')
    (1,14,'C','protected') (1,14,'D','private OR protected')
    (1,14,'E','All of the above') (1,15,'A','(C), (D) &amp; (E)')
    (1,15,'B','(D) ') (1,15,'C','(A), (D) &amp; (E)') (1,15,'D','(D) &amp; (E) ')
    (1,15,'E','(A)')</p>
    
    <p>===== users data ====</p>
    
    <p>(1,'1@gmail.com','','George','Ronald','','','Atlanta','GA','30303')
    (2,'2@gmail.com','','Mary','Erikson','','','San Diego','CA','91901')
    (3,'3@gmail.com','','John','Washington','','','Atlanta','GA','30314')</p>
    
    <p>====enrolls data=====</p>
    
    <p>(1,1,to_date('2012/02/15 10:00:00', 'yyyy/mm/dd
    hh24:mi:ss'),to_date('2012/02/22 10:00:00', 'yyyy/mm/dd hh24:mi:ss')
    (2,1,to_date('2012/02/15 10:00:00', 'yyyy/mm/dd
    hh24:mi:ss'),to_date('2012/02/22 10:00:00', 'yyyy/mm/dd hh24:mi:ss')
    (3,1,to_date('2012/02/17 10:00:00', 'yyyy/mm/dd
    hh24:mi:ss'),to_date('2012/02/24 10:00:00', 'yyyy/mm/dd hh24:mi:ss')
    (1,3,to_date('2012/02/17 10:00:00', 'yyyy/mm/dd
    hh24:mi:ss'),to_date('2012/02/24 10:00:00', 'yyyy/mm/dd hh24:mi:ss')
    (2,3,to_date('2012/02/20 10:00:00', 'yyyy/mm/dd
    hh24:mi:ss'),to_date('2012/02/27 10:00:00', 'yyyy/mm/dd hh24:mi:ss')
    (3,3,to_date('2012/02/20 10:00:00', 'yyyy/mm/dd
    hh24:mi:ss'),to_date('2012/02/27 10:00:00', 'yyyy/mm/dd hh24:mi:ss')</p>
    
    <p>===userResponse data====</p>
    
    <p>(1,1,1,'A') (1,1,2,'B') (1,1,3,'A') (1,1,4,'B') (1,1,5,'N')
    (1,1,6,'C') (1,1,7,'D') (1,1,8,'A') (1,1,9,'B') (1,1,10,'B')
    (1,1,11,'A') (1,1,12,'B') (1,1,13,'A') (1,1,14,'A') (1,1,15,'A')</p>
    
    <p>(2,1,1,'B') (2,1,2,'B') (2,1,3,'E') (2,1,4,'C') (2,1,5,'D')
    (2,1,6,'A') (2,1,7,'C') (2,1,8,'B') (2,1,9,'B') (2,1,10,'A')
    (2,1,11,'A') (2,1,12,'B') (2,1,13,'B') (2,1,14,'A') (2,1,15,'A')</p>
    
    <p>(3,1,1,'C') (3,1,2,'C') (3,1,3,'D') (3,1,4,'D') (3,1,5,'A')
    (3,1,6,'A') (3,1,7,'D') (3,1,8,'D') (3,1,9,'A') (3,1,10,'A')
    (3,1,11,'B') (3,1,12,'B') (3,1,13,'A') (3,1,14,'A') (3,1,15,'C')</p>
    
    <p>(1,3,1,'N') (1,3,2,'A') (1,3,3,'A') (1,3,4,'B') (1,3,5,'B')
    (1,3,6,'C') (1,3,7,'D') (1,3,8,'A') (1,3,9,'A') (1,3,10,'B')</p>
    
    <p>(2,3,1,'B') (2,3,2,'C') (2,3,3,'A') (2,3,4,'C') (2,3,5,'B')
    (2,3,6,'D') (2,3,7,'D') (2,3,8,'D') (2,3,9,'A') (2,3,10,'A')</p>
    
    <p>(3,3,1,'B') (3,3,2,'A') (3,3,3,'A') (3,3,4,'B') (3,3,5,'B')
    (3,3,6,'C') (3,3,7,'D') (3,3,8,'A') (3,3,9,'A') (3,3,10,'B')</p>
  </blockquote>