i have used sql server as database my problem is how do the restricted special character and strange type of web url get inserted into the tables.?

I had encountered the same situation where dummy texts were getting inserted in my table even though, My script had input validations

From this case, I can say that you first need to identify that scenario where user is putting the wrong data but your JavaScript couldn't spot it (and allowing data to be inserted in the table)

Below are the few tips which you can try-

1) Try to input above text from your UI and monitor the table on each input.See where it fails
2) Run the SQL profiler while conducting the test#1
3) If you are using SQL proc to insert the data into table (you must use SQL Proc, good to avoid SQL injection) then insert all the parameters along with UserId (id of logged-in user) in to another log table. Spot the user entry where the dirty entries coming from. Connect with that user and understand which scenarios he/she is running
Try to debug your JavaScript for the same scenario

Hope this helps
RDBurmon