Update Volume using query in SQL

• caojunhe24

  Ten Centuries

  Points: 1334

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  September 24, 2018 at 7:40 am

  #408544

  hi experts,

  I have one simple question here about update the value using query itself as shown below.
  is there a simple way to update Volume column using query column?

  first 4 rows will return same value,
  

  thanks
  Austin

• caojunhe24

  Ten Centuries

  Points: 1334

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  September 24, 2018 at 8:07 am

  #2006740

  Im thinking add seq number to the table and using seq to update each row in the table but am not sure. any suggestion?

  declare @seq int =1

  declare @seq_max int = (select max(seq) from [AdventureWorksDW2008R2].[dbo].[test])

  declare @sql varchar(max)= (select query from [AdventureWorksDW2008R2].[dbo].[test] where seq = @seq)

  while (@seq <= @seq_max)

  update a

  set a.volume = ??????

  from [AdventureWorksDW2008R2].[dbo].[test]a

  where seq = @seq

  @seq =@seq +1

• ChrisM@Work

  SSC Guru

  Points: 186127

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  September 24, 2018 at 8:54 am

  #2006753

  caojunhe24 - Monday, September 24, 2018 7:40 AM

  hi experts,

  I have one simple question here about update the value using query itself as shown below.
  is there a simple way to update Volume column using query column?

  first 4 rows will return same value,
  

  thanks
  Austin

  Please define exactly what content you want in the [volume] column and how it's derived.

  ^{“Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw}

  For fast, accurate and documented assistance in answering your questions, please read this article.
  Understanding and using APPLY, (I) and (II) Paul White
  Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden

• caojunhe24

  Ten Centuries

  Points: 1334

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  September 24, 2018 at 11:08 am

  #2006787

  Hi guru,

  the volume should be float value and it's derived from query column{select count(*) from ..}

  e.g in the first row if you excute the select query from [query] column it will have 20 this 20 should be in [Volume] column.

  thanks
  Austin