WebJun 3, 2024 · 源数据:. 行转列图一. SELECT user_name , MAX(CASE course WHEN '数学' THEN score ELSE 0 END ) 数学, MAX(CASE course WHEN '语文' THEN score ELSE 0 END ) 语文, MAX(CASE course WHEN '英语' THEN score ELSE 0 END ) 英语 FROM student GROUP BY USER_NAME; 行转列后:. 行转列图二. WebMay 30, 2024 · 这里就要用到SQL语句拼接了。. 具体就是下面的语句:. SELECT GROUP_CONCAT(DISTINCT CONCAT( 'SUM (IF (c.coursenm = ''', c.coursenm, ''', s.scores, 0)) AS ''', c.coursenm, '''' ) ) FROM courses c; 得到的结果就是. SQL拼接.png. 对,没错,就是我们上面进行 行转列 查询要用的语句,那样就不用 ...
SQL Server 如何实现行转列-百度经验
WebMar 22, 2024 · For each use case, cover how a subquery interacts with outer queries and the T-SQL for implementing the use case. Review excerpts from each example to show the value of implementing the use case. Solution. For readers who want help with subquery syntax, performance, or keyword issues, you may find what you need in one of these prior tips … WebApr 5, 2024 · CASE: indicates a condition loop has been started and that the conditions will follow. WHEN: indicates the start of a condition that should be checked by the query. … forrum investments atlanta ga
How to Remove Duplicate Records in SQL - Database Star
Web方法一:使用case when表达式,灵活提取各科目(subject)的值作为单独的列,命令示例如下。 select name as 姓名, max(case subject when '语文' then result end) as 语文, … WebAug 9, 2024 · 实现行转列有两种方式,方式一,可通过case when 实现;方式二:可通过pivot实现;以下是分别使用这两种方式实现的具体语法。 方式一:CASE WHEN SQL 查询语句如下所示: WebMay 29, 2024 · impala查询的,有很多sql都用了这个语句,我想知道用处是啥? cloudera java 有问必答 2024-03-14 10:41 digital desk clock battery powered