SQL Update

sorry, but i dont understand how this wil work.

update [WARD_SCD2_HISTORY]
set

 = 
case when @update_value is null 
then [Code] 
else @update_value                               
end 

Select allOpen in new window

the code chould be any value, so i cannot use the same value

all its done is set all the values in the code column to null.

i want to use previous value if null

i've been looking at CTE and coalesce

still not what i am looking for.

sorry to be a pain.
Incorrect syntax near the keyword 'from'.

this works for reference.


UPDATE  TABLE  
SET     Code = c2.Code  
OUTPUT  Inserted.*  

FROM    TABLEc  
        INNER JOIN (  
          SELECT  c.[DateCreated]
                  , c.[BusinessKey]
                  , Code = COALESCE(c.Code, cprevious.Code)
          FROM    TABLEc
                  INNER JOIN (
                    SELECT  c.[DateCreated]
                            , c.[BusinessKey]
                            , MaxDate = MAX(cdates.[DateCreated])
                    FROM    TABLEc
                            LEFT OUTER JOIN (
                              SELECT  [DateCreated]
                                      , [BusinessKey]
                              FROM    TABLE
                            ) cdates ON cdates.[DateCreated] < c.[DateCreated] AND cdates.[BusinessKey] = c.[BusinessKey]
                    GROUP BY
                            c.[DateCreated], c.[BusinessKey]
                  ) cmax ON cmax.[DateCreated] = c.[DateCreated] AND cmax.[BusinessKey] = c.[BusinessKey]                  
                  LEFT OUTER JOIN TABLE cprevious ON cprevious.[DateCreated] = cmax.MaxDate AND cprevious.[BusinessKey] = cmax.[BusinessKey]
        ) c2 ON c2.[DateCreated] = c.[DateCreated]  
                AND c2.[BusinessKey] = c.[BusinessKey]

partly answered.