SQL Server Execute update result sets from dynamic query writer - sql-server-2008

Question

This link is where I found part of an answer to my problem.
SQL replace all NULLs
Simon posted
"Be a boss. Write something like:
select 'update ' + table_name + ' set [' + column_name + '] = '''' where [' + column_name + '] is null'
from tempdb.information_schema.columns
where table_name = 'YourTableName'
It'll spit out a big ol' query for you.
You're welcome"
But I would like to know if there a way to use the results set in a parameter and execute all of the update statements.
I tried something like this
DECLARE #sql2 AS NVARCHAR(MAX) = N'
SELECT ''UPDATE '' + table_name + '' SET ['' + column_name + ''] = '''''''' WHERE ['' + column_name + ''] IS NULL''
FROM tempdb.information_schema.columns
WHERE table_name = ''##tempF'''
EXEC sp_executesql #stmt = #sql2;
DECLARE #sql3 AS NVARCHAR(MAX);
SET #sql3 = (SELECT #sql2);
EXEC sp_executesql #stmt = #sql3;
but it two result sets like listed below:
UPDATE ##tempF SET [claimid] = '' WHERE [claimid] IS NULL
UPDATE ##tempF SET [hdr_status] = '' WHERE [hdr_status] IS NULL
UPDATE ##tempF SET [memid] = '' WHERE [memid] IS NULL
Many thanks to you all.
Cheers!
Tim

Answer 1

Like this
--initialize variables
DECLARE #UpdateColumns varchar(max) = ''
DECLARE #IsNullColumns varchar(max) = ''
SELECT
#UpdateColumns = #UpdateColumns + ',[' + COLUMN_NAME + '] = ISNULL([' + COLUMN_NAME + '],'''')',
#IsNullColumns = #IsNullColumns + ' OR [' + COLUMN_NAME + '] IS NULL'
FROM tempdb.information_schema.columns
WHERE table_name = '##tempF'
This should fill in the two variables with the following values:
#UpdateColumns = ',[claimid] = ISNULL([claimid],''''),[hdr_status] = ISNULL([hdr_status],''''),[memid] = ISNULL([memid],'''')'
#IsNullColumns = ' OR [claimid] IS NULL OR [hdr_status] IS NULL OR [memid] IS NULL'
Then you need to assemble it all (remember to remove the first characters of each of the variables (the STUFF function is great for that):
DECLARE #qry varchar(max) = 'UPDATE ##tempF SET '
+ STUFF(#UpdateColumns,1,1,'') + ' WHERE '
+ STUFF(#IsNullColumns,1,4,'') --the 4 in here is to get rid of ' OR ' (4 chars)
EXEC(#qry)