目录一、前言二、使用步骤1、函数的语法:2、实例3、查询字段结果为空则返回另一个字段补充知识:mysql判断字符串为NULL或者为空字符串总结一、前言
I have an rdf graph with several entries. Now I want to get all related triples to a gi开发者_开发百科ven id. This is my sparql query: