flask_water_quality/PGDB_Read.py

import json
import psycopg2




def query_database(cursor,nm_values):



    try:


        # 要查询的 nm 值列表


        # 参数化查询
        query = """
            SELECT 
                nm, v
            FROM realtimedata
            WHERE nm IN %s;
        """

        # 执行 SQL 查询，传递一个元组作为 IN 子句的参数
        cursor.execute(query, (tuple(nm_values),))



        # 获取查询结果
        results = cursor.fetchall()
        #json_str = results = json.dumps(results)
        # 将列表转换为字典
        # 构建字典，根据值的类型转换为 int 或 float
        result_dict = {row[0]: float(row[1]) if '.' in row[1] else int(row[1]) for row in results}

        # 将字典转换为 JSON 字符串
        json_str = json.dumps(result_dict, ensure_ascii=False, indent=4)

        # 打印 JSON 字符串

        print("数据库连接已关闭")
        return json_str


    except psycopg2.Error as e:
        print("数据库操作出错")
        print("错误详情:", e)