Ivan Sergio Borgonovo <mail(at)webthatworks(dot)it> writes:
> I've
> case when ''=extinput then null else extinput::timestamp end
> now when extinput='' it seems that else extinput::timestamp get
> evaluated anyway and I get:
> invalid input syntax for type timestamp: ""
I think you are leaving off a large percentage of the truth.
Is "extinput" actually a variable, or do you mean that you are
substituting a literal string there?
regards, tom lane