Datawhale 知识图谱组队学习 Task 5 Neo4j 图数据库查询

Neo4j图数据库查询

• 1. 连接neo4j数据库之后，在浏览器中使用http://localhost:7474/browser/网址查看数据库，初始账户跟密码都是neo4j

• 2. 首先查看图数据库

     
     
     
     

     双击某一个实体可以看到该实体与其他实体之间的关系

     
     

• 查询疾病实体

  
  
  
  

  根据疾病查询症状和药品，实体之间的关系可以从代码中看到

  
  

MATCH (d:Disease)-[:HAS_SYMPTOM]->(s) WHERE d.name='糖尿病' RETURN d.name,s.name

MATCH (d:Disease)-[:HAS_DRUG]->(drug) WHERE d.name='糖尿病' RETURN d.name,drug.name

基于知识图谱的问题系统主体类AnswerSearching介绍

class AnswerSearching:
    def __init__(self):
        pass
    # 主要是根据不同的实体和意图构造cypher查询语句
    def question_parser(self, data):
        """
        主要是根据不同的实体和意图构造cypher查询语句
        :param data: {"Disease":[], "Alias":[], "Symptom":[], "Complication":[]}
        :return:
        """
        pass
    # 将问题转变为cypher查询语句
    def transfor_to_sql(self, label, entities, intent):
        """
        将问题转变为cypher查询语句
        :param label:实体标签
        :param entities:实体列表
        :param intent:查询意图
        :return:cypher查询语句
        """
        pass
    # 执行cypher查询，返回结果
    def searching(self, sqls):
        """
        执行cypher查询，返回结果
        :param sqls:
        :return:str
        """
        pass
    # 根据不同意图，返回不同模板的答案
    def answer_template(self, intent, answers):
        """
        根据不同意图，返回不同模板的答案
        :param intent: 查询意图
        :param answers: 知识图谱查询结果
        :return: str
        """
        pass

代码分模块介绍

• 在Python中我们使用py2neo进行查询
• 首先安装py2neo,pip install py2neo
• 连接上neo4j数据库

 from py2neo import Graph 
    graph = Graph("http://localhost:7474", username="neo4j", password="neo4j")

• 根据不同的实体和意图构造cypher查询语句

 def question_parser(data):
        """
        主要是根据不同的实体和意图构造cypher查询语句
        :param data: {"Disease":[], "Alias":[], "Symptom":[], "Complication":[]}
        :return:
        """
        sqls = []
        if data:
            for intent in data["intentions"]:
                sql_ = {}
                sql_["intention"] = intent
                sql = []
                if data.get("Disease"):
                   sql = transfor_to_sql("Disease", data["Disease"], intent)
                elif data.get("Alias"):
                    sql = transfor_to_sql("Alias", data["Alias"], intent)
                elif data.get("Symptom"):
                    sql = transfor_to_sql("Symptom", data["Symptom"], intent)
                elif data.get("Complication"):
                    sql = transfor_to_sql("Complication", data["Complication"], intent)

                if sql:
                    sql_['sql'] = sql
                    sqls.append(sql_)
        return sql

• 将问题转变为cypher查询语句

def transfor_to_sql(label, entities, intent):
        """
        将问题转变为cypher查询语句
        :param label:实体标签
        :param entities:实体列表
        :param intent:查询意图
        :return:cypher查询语句
        """
        if not entities:
            return []
        sql = []

        # 查询症状
        if intent == "query_symptom" and label == "Disease":
            sql = ["MATCH (d:Disease)-[:HAS_SYMPTOM]->(s) WHERE d.name='{0}' RETURN d.name,s.name".format(e)
                   for e in entities]
        # 查询治疗方法
        if intent == "query_cureway" and label == "Disease":
            sql = ["MATCH (d:Disease)-[:HAS_DRUG]->(n) WHERE d.name='{0}' return d.name,d.treatment," \
                   "n.name".format(e) for e in entities]
         # 查询治疗周期
        if intent == "query_period" and label == "Disease":
            sql = ["MATCH (d:Disease) WHERE d.name='{0}' return d.name,d.period".format(e) for e in entities
        ...

• 执行cypher查询，返回结果

def searching(sqls):
        """
        执行cypher查询，返回结果
        :param sqls:
        :return:str
        """
        final_answers = []
        for sql_ in sqls:
            intent = sql_['intention']
            queries = sql_['sql']
            answers = []
            for query in queries:
                ress = graph.run(query).data()
                answers += ress
            final_answer = answer_template(intent, answers)
            if final_answer:
                final_answers.append(final_answer)
        return final_answers

• 根据不同意图，返回不同模板的答案

def answer_template(intent, answers):
        """
        根据不同意图，返回不同模板的答案
        :param intent: 查询意图
        :param answers: 知识图谱查询结果
        :return: str
        """
        final_answer = ""
        if not answers:
            return ""
        # 查询症状
        if intent == "query_symptom":
            disease_dic = {}
            for data in answers:
                d = data['d.name']
                s = data['s.name']
                if d not in disease_dic:
                    disease_dic[d] = [s]
                else:
                    disease_dic[d].append(s)
            i = 0
            for k, v in disease_dic.items():
                if i >= 10:
                    break
                final_answer += "疾病 {0} 的症状有：{1}\n".format(k, ','.join(list(set(v))))
                i += 1
            ...