摘要:
一句话:浏览器从一个域名的网页去请求另一个域名的资源时,域名、端口、协议任一不同,都是跨域浏览器控制台跨域提示: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'null' i 阅读全文
摘要:
ORACLE select * from tableselect name,sno from table 去重select distinct country from table where子语句 提取满足特定条件的记录select * from table where country='CN' A 阅读全文