文章浏览阅读2.2k次。今天为写一条SQL困扰了很久首先先贴两条sql，大家看看有啥区别select * from all_txt A where id=(SELECT id from all_txt where A.key_value = key_value ORDER BY release_time DESC limit 1);select * from (select *,max(release_time) as_sql group by 难学...
文章浏览阅读1.7k次。本章内容对应官网：https://nightlies.apache.org/flink/flink-docs-release-1.12/dev/table/streaming/time_attributes.html1.时间属性介绍Time attributes can be part of every table schema.They are defined when creating a table from a CREATE TABLE DDL or a DataStre......
文章浏览阅读1k次。检索数据：检索单个列：SELECT pname FROM product 检索多个列：SELECT pname,market_price,is_hot FROM product 检索所有列：SELECT * FROM product 过滤检索结果中的重复数据：SELECT DISTINCT market_price FROM productDISTINCT关键字：1、返回......
