How can I find out which digital libraries include a given journal? When I am looking for a journal online, I have to do search for it in every electronic database one by one.

Is there an easy way to find which electronic databases provide that journal? 

I am doing legal research.
Worldcat.org will give you this information. Search for the journal by name, click on it in search results, and look under "Find a copy online".

For example, "International Construction Law Review" appears to be available in two digital libraries: