Sql server 2008字段类型说明一览
sqlserver2008中个字段的详细注解
http://blog.csdn.net/jingzhishen/article/details/6799678
Sql server 2008字段类型说明一览
http://database.51cto.com/art/201009/228304.htm
char、varchar、nchar、nvarchar的区别
http://blog.csdn.net/spring21st/article/details/3298536
