merge (:Test{name:‘ycw’})-[r:R]->(n:New{name:‘ycw’}) set r.position = r.position+'c’ 怎么判断c在不在r.position中

最终答案 merge (:Test{name:‘ycw’})-[r:R]->(n:New{name:‘ycw’}) with r where none(x in r.position where x=‘d’ ) set r.position=r.position+‘d’