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語(yǔ)法：row_number() over(partition by column order by column)
簡(jiǎn)單的說(shuō)row_number()從1開始，為每一條分組記錄返回一個(gè)數(shù)字，這里的row_number() over (order by cylh desc) 是先把xlh列降序，再為降序以后的每條cylh記錄返回一個(gè)序號(hào)。

示例：

SQL使用ROW_NUMBER() OVER函數(shù)生成序列號(hào)

分析：row_number() over (partition by col1 order by col2) 表示根據(jù)col1分組，在分組內(nèi)部根據(jù) col2排序，而此函數(shù)計(jì)算的值就表示每組內(nèi)部排序后的順序編號(hào)（組內(nèi)連續(xù)的唯一的)

也可這樣使用：row_number() over (order by col2)

例子：

建立測(cè)試表，并插入測(cè)試數(shù)據(jù)

				?

									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)

執(zhí)行腳本自動(dòng)生成行號(hào)并按cylh進(jìn)行排序（滑動(dòng)查看代碼）

				?

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

結(jié)果如下：

SQL使用ROW_NUMBER() OVER函數(shù)生成序列號(hào)

注意：在使用over等開窗函數(shù)時(shí)，over里頭的分組及排序的執(zhí)行晚于“where，group by，order by”的執(zhí)行。

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原文鏈接：https://www.cnblogs.com/since-1995/p/15629029.html