Question

我在SQL Server 2012中有两个表

的数据库

第一个表格列是：

isSymbolicLink

第二个表格列是：

 | Student_ID , Subject_ID , Subject_score , Subject_mark |
 |--------------------------------------------------------|
 |     1      |    1       |     92        |     ?        |
 |     1      |    2       |     88        |     ?        |
 |____________|____________|_______________|______________|

我想编写一个查询以从第二个表中获取|Score_ID | Subject_mark | |________________________| | 100 | A+ | | 95 | A | | 90 | B+ | | 85 | B | | 80 | c | | 75 | E | |_________|______________|并将其放在Subject_mark的第一个表中

Subject_mark

Answer 1

我正在打电话，所以我稍后要检查一下，因为它似乎有些不对劲，但尝试类似

Update table_1 
Set Subject_mark = (select Subject_mark from table_2 
                    where Score_ID <= (select Subject_score) 
                    and Score_ID > (select Subject_score - 5))

使用给定的样本数据执行示例：

DECLARE @FirstTable TABLE (Student_ID INT, Subject_ID INT, Subject_score INT, Subject_mark VARCHAR(3))

INSERT INTO @FirstTable (Student_ID, Subject_ID, Subject_score, Subject_mark)
VALUES 
 (1, 1, 92, NULL),
 (1, 2, 88, NULL)

DECLARE @SecondTable TABLE (Score_ID INT, Subject_mark VARCHAR(3))

INSERT INTO @SecondTable (Score_ID, Subject_mark)
VALUES
 (100, 'A+'),
 (95 , 'A'),
 (90 , 'B+'),
 (85 , 'B'),
 (80 , 'C'),
 (75 , 'E')

UPDATE @FirstTable 
SET Subject_mark = (SELECT Subject_mark 
                    FROM @SecondTable 
                    WHERE Score_ID <= (SELECT Subject_score) AND 
                          Score_ID > (SELECT Subject_score - 5))

SELECT * FROM @FirstTable

Answer 2

鉴于商标被分类为每个5分的差异，这应该有效。

UPDATE t1
SET t1.Subject_mark = CASE WHEN t1.Subject_score < 75 THEN 'E' ELSE t2.Subject_mark END
FROM FirstTable t1
LEFT OUTER JOIN SecondTable t2 ON t1.Subject_score <= t2.Score_ID AND t1.Subject_score > t2.Score_ID - 5;

我想查询读取学生的科目分数

2 个答案: