[导入]Trim a spaces only string in Oracle

Suppose we have a spaces only string ' ',

In MS SQL Server,
Trim(' ') =''
Length(Trim(' ')) =0

However, in Oracle,
Trim(' ') is null
Length(Trim(' ')) is null

文章来源:http://zouyu.blogspot.com/2005/08/trim-spaces-only-string-in-oracle.html