随笔分类 -  sql _常用问题

sql常用问题(一)
摘要：一、sql要掌握 1、sum select sum(score) from table 2、group select name, sum(score) from table group by 3、avg() SELECT AVG(OrderPrice) AS OrderAverage FROM Or 阅读全文
posted @ 2018-08-07 20:26 抽象Java 阅读(175) 评论(0) 推荐(0)