What are projection and selection

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What is the difference between projection and selection? Is it:

  • Projection --> for selecting the columns of table; 
  • Selection ---> to select the rows of table?

So are projection and selection vertical and horizontal slicing respectively? 

Sep 10, 2022 in Database by Kithuzzz
• 38,010 points
6,164 views

1 answer to this question.

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Projection means choosing which columns (or expressions) the query shall return.

Selection means which rows are to be returned.

I hope this helps you.

answered Sep 12, 2022 by narikkadan
• 63,420 points

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