T-SQL

How to find and remove hidden characters and invisible whitespace when LTrim, RTrim not work

SQL icon baseSometimes it can happen, that you compare two strings, which looks exactly sames, but they are processed as not equal. Also when you use SELECT DISTINCT and still there are rows that looks same, like DISTINCT is not working. Dimensional attribute in OLAP can return errors for duplicities even you used DISTINCT for dimension. This is the right time to search invisible/hidden characters in string.  RTrim and LTrim function not stripping whitespace.




How to alter column with default constraint in MSSQL

SQL_icon_base.jpgWhen you try alter column in MSSQL 2005 from one datatype to other with some default value by ALTER TABLE xxx ALTER COLUMN column_name you get error about existing constraint. Unfortunately there is nothing like CASCADE CONSTRAINT. You must DROP constraint first and then you can ALTER column and finally you have to create CONSTRAINT again. I will show you easy way, how to do it.