NVARCHAR (MAX) TO PRINT DYNAMIC SQL QUERY TO A SQL FILE

Question

Hi 
I have a requirement where i need to write an SP which would construct a huge query using dynamic SQL and save the Dynamic query to a file. 
The Dynamic SQL Variable I am using as @NVARCHAR(MAX) but since the query being built is large (>4000 characters), I am not able to select it into a table. PRINT @SQL prints the whole query but SELECT @SQL prints only upto 4000 characterrs. 
And I need to save this huge dynamix sql to a file using the SP.
Any thoughts as to how i can achieve this?
Rajiv

Answer 1

This is a know problem with dynamic SQL nvarchar(max) concatenation.
See below for correct assembly of large SQL strings:
CREATE table #temp(qry nvarchar(max));
declare @cmd nvarchar(max);
SELECT @cmd=CONCAT(CONVERT(nvarchar(max),N'SELECT '),
CONVERT(nvarchar(max),REPLICATE (N'A',4000)),
CONVERT(nvarchar(max),REPLICATE (N'A',4000)),
CONVERT(nvarchar(max),REPLICATE (N'A',4000)),
CONVERT(nvarchar(max),REPLICATE (N'A',4000)),
CONVERT(nvarchar(max),N'FROM SYS.TABLES'));
insert into #temp SELECT @cmd;
select * from #temp;
select len(qry), datalength(qry) from #temp;
-- 16022 32044
drop table #temp;
Dynamic SQL:  http://www.sqlusa.com/bestpractices/dynamicsql/
Kalman Toth Database & OLAP Architect
SQL Server 2014 Design & Programming
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