摘要:
1、创建只读角色 CREATE ROLE readaccess; 2、授予对现有表的访问权限 GRANT USAGE ON SCHEMA public TO readaccess; GRANT SELECT ON ALL TABLES IN SCHEMA public TO readaccess; 阅读全文
摘要:
#numpy中arrary与pandas中series、DataFrame区别#arrary生成数组,无索引、列名;series有索引,且仅能创建一维数组;DataFrame有索引、列名import numpy as npimport pandas as pd #numpy基本用法print(np. 阅读全文