我们如何在 SQL 服务器 2008 R2 中使用 LAG()？

Question

SELECT
  CASE
    WHEN ser.[Department Name] = LAG(SER.[Department Name]) OVER (ORDER BY SER.[Department Name]) THEN ''
    ELSE SER.[Department Name]
  END [Department Name] from department

Answer 1

您可以使用 APPLY :

SELECT (CASE WHEN d.[Department Name] = Prev_Dept
             THEN '' ELSE d.[Department Name]
        END) AS DepartmentName
FROM department d OUTER APPLY
     ( SELECT TOP (1) d1.[Department Name] AS Prev_Dept
       FROM department d1
       WHERE d1.? < d.?
       ORDER BY ? DESC
     ) AS Pd;

? 表示标识唯一数据序列的标识列。

我们如何在 SQL 服务器 2008 R2 中使用 LAG()？

How can we use LAG() in SQL server 2008 R2?

sql-server

sql-server-2008-r2