How do I swap column values in sql server 2008?

I have a table called Employee

 Eno     ename     AttributeValue      AttributeName  
 1       aa           a123             abc
 2       bbb          b123             dcf
 3       cc           c7sd             wew3

I want to swap the data from column AttributeValue to AttributeName and AttributeName to AttributeValue

For Example:

Eno     ename     AttributeValue   AttributeName  
1       aa        abc              a123
2       bbb       dcf              b123
3       cc        wew3             c7sd

Solution 1:

UPDATE employee
SET AttributeValue = AttributeName, 
    AttributeName = AttributeValue

However, unless both columns have the exact same definition, you risk losing information.

Solution 2:

Update employee
Set attributeValue = attributeName,
    attributeName = attributeValue

Solution 3:

update Employee set AttributeValue = AttributeName, AttributeName = AttributeValue