SQL使用ROW_NUMBER() OVER函数生成序列号

语法:row_number() over(partition by column order by column)
简单的说row_number()从1开始,为每一条分组记录返回一个数字,这里的row_number() over (order by cylh desc) 是先把xlh列降序,再为降序以后的每条cylh记录返回一个序号。

示例: 

分析:row_number() over (partition by col1 order by col2) 表示根据col1分组,在分组内部根据 col2排序,而此函数计算的值就表示每组内部排序后的顺序编号(组内连续的唯一的)

也可这样使用:row_number() over (order by col2)

例子:

建立测试表,并插入测试数据

 create table test_row_number_01(
       cmzh varchar(10) not null,
       cylh varchar(10) null,
       mje money null,
);


insert into test_row_number_01(cmzh,cylh,mje) values (2106000011,20281997,10.50)
insert into test_row_number_01(cmzh,cylh,mje) values(2106000010,20281996,10.50)
insert into test_row_number_01(cmzh,cylh,mje) values(2106000008,20281995,0.00)
insert into test_row_number_01(cmzh,cylh,mje) values(2106000006,20281994,9.50)
insert into test_row_number_01(cmzh,cylh,mje) values(2106000004,20281993,5.50)
insert into test_row_number_01(cmzh,cylh,mje) values(2106000001,20281992,10.50)
insert into test_row_number_01(cmzh,cylh,mje) values(2106000002,20281992,10.50)
insert into test_row_number_01(cmzh,cylh,mje) values(2106000007,20217280,0.00)
insert into test_row_number_01(cmzh,cylh,mje) values(2106000009,20172458,5.50)
insert into test_row_number_01(cmzh,cylh,mje) values(2106000005,20121813,0.00)


执行脚本自动生成行号并按cylh进行排序(滑动查看代码)

select row_number()over(order by cylh desc) as rownum,* from test_row_number_01


结果如下:

 注意:在使用over等开窗函数时,over里头的分组及排序的执行晚于“wheregroup byorder by”的执行。

到此这篇关于sql使用row_number() over函数生成序列号的文章就介绍到这了,更多相关sql用row_number() over生成序列号内容请搜索www.887551.com以前的文章或继续浏览下面的相关文章希望大家以后多多支持www.887551.com!

(0)
上一篇 2022年3月21日
下一篇 2022年3月21日

相关推荐