Question

我的桌子上有一些课程标签，如

Subject | Course | 
ACC     | 201
ACC     | 843
ACC     | 843I
ACC     | 850
ACC     | 930

我使用此SQL获取ACC 843，ACC 843I和ACC850：

select Subj_Code, crse_code
        from section_info
        Where (crse_code between '800' and '899') and subj_code = 'ACC'
        order by crse_code

但不知何故，这错过了843I。我怎样才能使这项检查有效？

感谢。

Answer 1

select Subj_Code, crse_code
        from section_info
        Where (cast(left(crse_code,3) as int) as num between 800 and 899) and subj_code = 'ACC'
        order by crse_code

希望这有效，试一试让我知道。谢谢！

Answer 2

假设课程名称的固定格式为3位数后跟可选字母，您只需比较该列的前3个字符即可。此外，由于前3个字符始终为数字，因此您可能希望在比较之前将它们转换为数字。您的查询将变为这样：

select Subj_Code, crse_code
from section_info
Where (cast(left(crse_code,3) as int) between 800 and 899) and subj_code = 'ACC'
order by crse_code

Answer 3

试试这个：

WHERE crse_code LIKE '8%'

Answer 4

WITH Orderedcourses AS
(
    SELECT Subj_Code, crse_code,
    ROW_NUMBER() OVER (ORDER BY cast(left(crse_code,3) as int) )AS RowNumber
    FROM Sales.SalesOrderHeader 
) 
SELECT Subj_Code, crse_code, RowNumber  
FROM Orderedcourses
WHERE RowNumber BETWEEN '800' and '899';

这是一个公用表表达式，我创建该表达式来存储用于对课程编号列进行排序的rownumber，然后通过查询调用它来获取列的有序结果。

ms sql中的字符串比较

4 个答案: