Nested case in Mysql

I need to write a SQL statement

• if TC is g开发者_StackOverflowreater than 1 return 500
• if TC is greater than .5 return 200
• if TC is greater than .25 return 100
• if TC is less than .25 return 50.

I know it's a nested case, using MySQL

EDIT: If table two has columns Id, TC, how do I use above to update the TC value.

select case when tc > 1 then 500
            when tc > .5 then 200
            when tc > .25 then 100
            else 50
       end
    ...

EDIT: Based on comments from OP

update YourTable
    set tc = case when tc > 1 then 500
                 when tc > .5 then 200
                 when tc > .25 then 100
                 else 50
             end