Department of Defense Emergency Response Capabilities Database Enhancement Act of 2017 This bill amends the John Warner National Defense Authorization Act for Fiscal Year 2007 to require the Department of Defense (DOD) to establish and maintain within one year a database of DOD emergency response capabilities that includes the cyber capabilities of the reserves and the National Guard of each state and territory that are important to national security and for response to domestic natural or man made disasters. DOD may use or modify a current database or tracking system if that will expedite and achieve compliance at a cost not greater than the cost of establishing a new database. DOD shall identify and revise the database information at least once every two years.