我該怎麼做`group by`部分匹配

Question

我在SQL-server中有一個表，其中的projectcodes和子項目代碼在相同的字段中。

的stucture是這樣

+----+------+-------------+-------+--------+--------+ 
| id | date | projectcode | debit | credit | budget | 
+----+------+-------------+-------+--------+--------+ 
| 1 | bla | A100  | bla 
| 2 | bla | A100.01  | 
| 3 | bla | A112  | 
| 4 | bla | A112.02 

我如何做一個選擇這樣

SELECT projectcode 
    , sum(debit) as debit 
    , sum(credit) as credit 
    , sum(budget) as budget 
FROM table1 
GROUP BY -insert-answer-here- 

我所要的輸出group by A100和A100.01和A100.x在一起，以及如A112 + A112.x

我該怎麼做？

我無法控制表的結構。

Answer 1

GROUP BY LEFT(projectcode ,CHARINDEX('.',projectcode + '.')-1) 

Answer 2

如果項目的代碼始終遵循相同的模式（cnnn/cnnn.nn），你可以得到的前四個字符：

group by substring(projectcode, 1, 4) 

Answer 3

也許這會工作：

SELECT Substring(projectcode, 1, 4) as Project 
    , sum(debit) as debit 
    , sum(credit) as credit 
    , sum(budget) as budget 
FROM table1 
GROUP BY Substring(projectcode, 1, 4)