Limit No Of Row Not Work

I am using phprunner 6.1
In Query-> sql

... WHERE (s.create_date >= curdate() - interval 1 month)

ORDER BY s.ID DESC limit 100
I added limit 100 and build the project, but not work.

In ...setting.php file, limit 100 is omitted automatically. $tstrOrderBy = "ORDER BY s.ID DESC";