Repeating Formulae

• eamonroche

  SSCommitted

  Points: 1678

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  September 8, 2003 at 8:59 am

  #81966

  the following statement doesnt seem to work:

  select

  gym + park + hall as mysum,

  3 * mysum + 56 as mysum_processed

  from my_table

  To get it to work I need to do the following:

  select

  gym + park + hall as mysum,

  3 * (gym + park + hall) + 56 as mysum_processed

  from my_table

  this seems INEFFICIENT to me as I am repeating my gym + park + hall formula.

  Do I have to repeat the formula???

  Thanks in advance!

  Eamon

• NPeeters

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  Points: 12535

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  September 8, 2003 at 10:22 am

  #473053

  I'm afraid you do have to repeat it. One way around it would be to use a subquery in the FROM clause, but I don't know about performance.

  
  
  select mysum,
  
         3 * mysum + 56 as mysum_processed
  
  from (select gym + park + hall as mysum
  
        from my_table) my_der_table
  
  

• eamonroche

  SSCommitted

  Points: 1678

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  September 8, 2003 at 1:46 pm

  #473104

  thanks npeeters. Looks like we have to live with it.

  strange that this is so as it seems so straightforward to do:

  select

  gym + park + hall as mysum,

  3 * mysum + 56 as mysum_processed

  from my_table

  -- well done to the Belgian tennis girls (clijsters and Hannan)