What is the difference between SUPER KEY and UNIQUE KEY...!??

Replies

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  vinci

  UNIQUE KEY DEFINES ALL THE ROWS IN TABLE UNIQUELY .AND BASICALLY OCCURS ONLY SINGLE UNIQUE KEY IN ONE TABLE WHILE SUPER KEY UNIQUELY IDENTIFY A TUPLE AND NOT ALL THE ROWS i.e NO TWO TU PLES HAVE SAME ATTRIBUTES IN SUPER KEY
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  TheV

  I am confused....!!! What is the difference between tuples and rows.
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  Manish Goyal

  TheV

  I am confused....!!! What is the difference between tuples and rows.

  Tuple is nothing but another name of rows in database
  
  
  Unique key is just a single attribute (Column) where as super key is a set of attributes
  
  However both have same function ie to identify rows of a table uniquely
• 

  TheV

  Thankyou Goyal....!
  
  But In wikipedia the defination of unique is a one column or a set of columns which Identify the tuples or row uniquely.
  
  First line, second sentence,,..Unique Key
• 

  Manish Goyal

  TheV

  Thankyou Goyal....!
  
  But In wikipedia the defination of unique is a one column or a set of columns which Identify the tuples or row uniquely.
  
  First line, second sentence,,..Unique Key

  unique key may or may not contain set of column , while super key is basically a set of attributes