What is the difference between unicode and non-unicode character types? Which one should I use? Nvarchar (unicode) or Varchar (non-unicode)?
If you can use non-unicode use it as it will be smaller and quicker (generally 70% smaller footprint), but if you need things like é or support other languages use unicode.
Unicode is the UNIVERSAL encoding system. This is supported by a non-profit organization (Unicode Consortium) to ensure that we can all understand each other clearly…not just internationally but historically as well.
To help you remember, the N in front of nvarchar or nchar stands for the National language character set (i.e. unicode). If your data structure might possibly expand to other languages, set it up to use a unicode datatype.
If you work with ssis at all you have likely seen the error "Cannot Convert between Unicode and Non Unicode String Data Type"
If you are going from non-unicode (varchar or char) to unicode (nvarchar or nchar) you will benefit transforming the data with the unicode string [dt_wstr] or unicode text stream [dt_ntext] depending on how lengthy the field is..
There is no reason for such a silly title or for the picture below except to make you think this post would be something interesting to read. There is no relationship between unicode and unicorns, nor will there ever be.
