Update records in table from CTE

sql sql-server tsql common-table-expression
Etienne picture Etienne · Jul 19, 2012 · Viewed 129.9k times · Source

I have the following CTE that will give me the DocTotal for the entire invoice.

 ;WITH CTE_DocTotal
 AS
 (
   SELECT SUM(Sale + VAT) AS DocTotal
   FROM PEDI_InvoiceDetail
   GROUP BY InvoiceNumber
 )

UPDATE PEDI_InvoiceDetail
SET DocTotal = CTE_DocTotal.DocTotal

Now with this result I want to enter into the column the DocTotal value inside PEDI_InvoiceDetail.

I know is not going to work and I know I am missing something, what is it?

Answer

GarethD picture GarethD · Jul 19, 2012

Updates you make to the CTE will be cascaded to the source table.

I have had to guess at your schema slightly, but something like this should work.

;WITH T AS
(   SELECT  InvoiceNumber, 
            DocTotal, 
            SUM(Sale + VAT) OVER(PARTITION BY InvoiceNumber) AS NewDocTotal
    FROM    PEDI_InvoiceDetail
)
UPDATE  T
SET     DocTotal = NewDocTotal

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