Store variable SQL Statement into a JSON variable

Question

I want to store a FOR JSON AUTO output in a variable.

But I want to use a variable select statement.

Something like this:

SET @SQLString = 'SELECT ID, Name FROM ' + @TableName + ' ';

SET @Body = (
   @SQLString + 'FOR JSON AUTO'
); 

Answer 1

Like this

declare @sql nvarchar(max) = 'select * from sys.objects'

declare @forJsonSql nvarchar(max) = concat('select @json = (',@sql, ' for json auto)')

--print @forJsonSql

declare @json nvarchar(max)
exec sp_executesql @forJsonSql, N'@json nvarchar(max) output', @json=@json output

select @json