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Mysql【ON DUPLICATE KEY UPDATE】Oracle【MERGE】实现批量新增/更新

Mysql按表字段分组排序，取每组数据的最值需求说明sql文rank() over()函数说明需求说明例如：有一张记录用户成绩的表 t_goal，表字段以及表数据如下：iduuidgoaltime156a2e88e-54f4-49f6-83dd-592ce1da63bc902022-05-18 09:00:00256a2e88e-54f4-49f6-83dd-592ce1da63bc922022-05-19 09:00:00356a2e88e-54f4

1、查询所有表名字，默认schema名字是publicSELECT tablenameFROM pg_tablesWHERE schemaname = 'public'2、查询已知表名tableName的所有字段的字段名、类型、是否为空、注释SELECT A.attname AS NAME, format_type(A.atttypid, A.atttypmod) AS TYPE, A.attnotnull AS NOTNULL, col_description(A.attreli

SQL Server 的日期函数一、当前时间二、格式化时间三、DATEDIFF()四、DATEADD()五、DATENAME(datepart,date)六、DATEPART(datepart,date)七、日期组成以及缩写一、当前时间select GETDATE()二、格式化时间-- yyyy-mm-dd-- 23select CONVERT(varchar(100), GETDATE(), 23)其他格式代号：测试数据时间：2021-01-02 12:26:01:220

表数据 拼接 去重，去空select ROW_NUMBER() over() as RN,tmp.* as SITE from( select B.A from ( select distinct field1 A from table1 union select distinct field2 A from table1 union select distin...