How to update Temp table by providing column name through variable - sql

Question

I have temp table generated by dynamic SQL query with different column name depends upon data. when I want to update temp table by given hard coded column name it works fine. but when I pass column name by variable it won't works
update #Temp
set #value = ''' + cast(#TempData as nvarchar(max)) + '''
where id = #CUserID
here #value holds column name like [Dusky Legend] this query won't works but
update #Temp
set [Dusky Legend] = ''' + cast(#TempData as nvarchar(max)) + '''
where id = #CUserID
this works properly ,
my problem is I have only way to provide column name by variable
this is my complete code
Declare #MarketID AS NVARCHAR(MAX) = '1.136903880';
Declare #UserID AS NVARCHAR(MAX) = '6a309d84-d1c6-434d-b9df-4f96a74da912';
declare #TempData as numeric = 1111111111;
declare ##values as NVARCHAR(MAX) ='';
DECLARE #colsSelect AS NVARCHAR(MAX);
DECLARE #colsLoop AS NVARCHAR(MAX);
DECLARE #query AS NVARCHAR(MAX);
SELECT #colsSelect = STUFF((SELECT distinct ',' +
'00' + ' as ' + QUOTENAME(name)
from RunnersInfoes AS t where marketID =#MarketID
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
, 1, 1, '');
SELECT #colsLoop = STUFF((SELECT distinct ',' +
QUOTENAME(name)
from RunnersInfoes AS t where marketID =#MarketID
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
, 1, 1, '');
--print #colsLoop
set #query=
'
;with cte
as
(
select
id, ParentId,0 AS Level,Share ,AccountTypeName,FirstName
from dbo.View_UserProfile
where View_UserProfile.id = ' + '''' + #UserID + '''' +'
union all
select
t.id, t.ParentId,Level + 1 AS Level,t.Share,t.AccountTypeName ,t.FirstName
from View_UserProfile t
inner join cte on t.ParentId = cte.id)
SELECT ID,AccountTypeName as Type,FirstName as Name, ' + #colsSelect + ' into #Temp from cte as t
--exec tempdb..sp_help #Temp
Declare #CUserID AS NVARCHAR(MAX)
DECLARE dynamic_cursor CURSOR FOR
select ID from #Temp
OPEN dynamic_cursor
FETCH NEXT FROM dynamic_cursor INTO #CUserID
WHILE ##FETCH_STATUS = 0
BEGIN
declare #pos as numeric = 0
declare #len as numeric = 0
declare #value as varchar(255)
WHILE CHARINDEX('','', ''' + #colsLoop +''', #pos+1)>0
BEGIN
set #len = CHARINDEX('','', ''' + #colsLoop +''', #pos+1) - #pos
set #value = SUBSTRING(''' + #colsLoop +''', #pos, #len)
PRINT #value
update #Temp set [Dusky Legend] = ''' + cast(#TempData as nvarchar(max)) + ''' where id = #CUserID
set #pos = CHARINDEX('','', ''' + #colsLoop +''', #pos+#len) +1
END
--print' + cast(#TempData as nvarchar(max)) +'
--update #Temp set [Dusky Legend] =''' + cast(#TempData as nvarchar(max)) + ''' where id = #CUserID
FETCH NEXT FROM dynamic_cursor INTO #CUserID
END
CLOSE dynamic_cursor
DEALLOCATE dynamic_cursor
select * from #Temp
'
execute (#query)

Answer 1

You need dynamic SQL.
declare #value varchar(64) = '[Dusky Legend]'
declare #TempData varchar(max) = 'some value'
declare #CUSerID int = 14
declare #sql varchar(max)
set #sql = '
update #Temp
set ' + #value + ' = ' + cast(#TempData as nvarchar(max)) + '
where id = ' + cast(#CUserID as varchar(256))
print(#sql)
--exec(#sql)
Side note, you may need a global TempTable depending on how you are doing this.