在其他情况下清空

Question

I'm updating multiple columns using case when. I want no action taken on cases not handled by when. I read this could be accomplished by using a begin end, but this doens't work for me.

My syntax is:

update site_configuration set value = 
    case 
        when attribute_name="hostname" then "abcdef" 
        when attribute_name="backend" then "ab" 
        when attribute_name="col" then "col" 
        else 
            begin 
            end
    end case 
where uid="abcdef";

Does this syntax look right?

Thanks

Answer 1

Use just

else `value`

In this case the value of the value column will be left the same

Instead you can add one more condition to your where

where uid="abcdef" AND attribute_name IN ('hostname', 'backend', 'col')

in this case you just omit else clause