Remove special characters from string in SQL server

I faced many times an issue to remove special characters from a string. Suppose you are working on searching concept and you have to remove the special characters from search string due to query performance, there are many solutions is available but T-SQL is quickly resolved this issue.

Following query may help you to resolve your issue.

DECLARE @expres  VARCHAR(50) = '%[~,@,#,$,%,&,*,(,),.,!]%'
SET @str = '(remove) ~special~ *characters. from string in sql!'
  WHILE PATINDEX( @expres, @str ) > 0
         SET @str = Replace(REPLACE( @str, SUBSTRING( @str, PATINDEX( @expres, @str ), 1 ),''),'-',' ')

PostgreSQL: DROP TABLE is not working

Problem: I want to drop my table, but I am not able to drop the table while I tried the query "DROP TABLE MyTable CASCADE;". ...