Question

我有一个问题。这是故事，我有学生标记表（表 A ）

Name    Course  Marks
Student 01  32472   44
Student 02  32472   80
Student 03  32472   67
Student 04  32472   76
Student 05  32472   56
Student 06  32472   98
Student 07  32472   13
Student 08  32472   68
Student 09  32472   84
Student 10  32472   93

我有奖章的表格（表 B ）。

Medel     Course    CutOff
Silver    32472      0-69
Gold      32472      70 -84
Platinum  32472      85 -100

请您帮我在SQL中获取以下表格（表格）。

Name    Course  Medal
Student 01  32472   Silver
Student 02  32472   Gold
Student 03  32472   Silver
Student 04  32472   Gold
Student 05  32472   Silver
Student 06  32472   Platinum
Student 07  32472   Silver
Student 08  32472   Silver
Student 09  32472   Gold
Student 10  32472   Platinum

我如何加入表A（学生标记表）和表B（奖章截止标记表）然后获得决赛桌？

非常感谢您的回答/评论。

谢谢加扬

Answer 1

编辑后：

;WITH CteMedals AS(
    SELECT *,
        rStart  = LEFT(CutOff, CHARINDEX('-', CutOff) - 1),
        rEnd    = SUBSTRING(CutOff, CHARINDEX('-', CutOff) + 1, LEN(CutOff) - CHARINDEX('-', CutOff))
    FROM TableB
)
SELECT
    a.Name, a.Course, ISNULL(b.Medal, 'Silver') AS Medal
FROM TableA a
OUTER APPLY(
    SELECT TOP 1 Medal
    FROM CteMedals
    WHERE
        a.Marks BETWEEN rStart AND rEnd
    ORDER BY rEnd DESC
)b

您可以使用OUTER APPLY：

SELECT
    a.Name, a.Course, ISNULL(b.Medal, 'Silver') AS Medal
FROM TableA a
OUTER APPLY(
    SELECT TOP 1 Medal
    FROM TableB
    WHERE
        a.Marks >= CutOff
    ORDER BY CutOff DESC
)b

在另一个数据表上迭代数据表并创建一个表

1 个答案: