About: http://webisa.webdatacommons.org/30278523

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Embed the *last* column in any kind of constraint; in my case it is a UNIQUE constraint but I assume this bug affects all types of constraints.
http://www.w3.org/ns/prov#wasQuotedFrom	php.net