您好我在SQL Server 2005中遇到SQL问题。
假设我有一个名为myTable的表，其数据如下：
| NAME | CREDIT | GRADE | YEAR | SEMESTER |
---------------------------------------------
| Name1 | 1 | A | 1 | 1 |
| Name2 | 4 | B | 1 | 1 |
| Name3 | 2 | E | 1 | 1 |
| Name4 | 7 | F | 1 | 1 |
| Name5 | 4 | A | 1 | 2 |
| Name6 | 3 | C | 1 | 2 |
| Name7 | 6 | D | 1 | 2 |
| Name8 | 1 | A | 1 | 2 |
| Name9 | 1 | A | 1 | 2 |
| Name10 | 1 | A | 1 | 2 |
| Name11 | 3 | C | 2 | 1 |
| Name12 | 6 | E | 2 | 1 |
| Name13 | 4 | C | 2 | 1 |
| Name14 | 2 | B | 2 | 2 |
| Name15 | 1 | A | 2 | 2 |
| Name16 | 1 | A | 2 | 2 |
| Name17 | 1 | A | 2 | 2 |
| Name18 | 5 | D | 3 | 1 |
| Name19 | 1 | A | 3 | 1 |
| Name20 | 1 | A | 3 | 1 |
| Name18 | 5 | D | 3 | 2 |
| Name19 | 1 | A | 3 | 2 |
| Name20 | 1 | A | 3 | 2 |
我想输出如下结果：
| NAM1 | CRDT1 | GRD1 | YEAR1 | SEMER1 | NAM2 | CRDT2 | GRD2 | YEAR2 | SEMES2 |
-----------------------------------------------------------------------------
| Name1| 1 | A | 1 | 1 |Name5 | 4 | A | 1 | 2 |
| Name2| 4 | B | 1 | 1 |Name6 | 3 | C | 1 | 2 |
| Name3| 2 | E | 1 | 1 |Name7 | 6 | D | 1 | 2 |
| Name4| 7 | F | 1 | 1 |Name8 | 1 | A | 1 | 2 |
|Name9 | 1 | A | 1 | 2 |
|Name10| 1 | A | 1 | 2 |
| Name11| 3 | C | 2 | 1 |Name14| 2 | B | 2 | 2 |
| Name12| 6 | E | 2 | 1 |Name15| 1 | A | 2 | 2 |
| Name13| 4 | C | 2 | 1 |Name16| 1 | A | 2 | 2 |
|Name17| 1 | A | 2 | 2 |
| Name18| 5 | D | 3 | 1 |Name18| 5 | D | 3 | 2 |
| Name19| 1 | A | 3 | 1 |Name19| 1 | A | 3 | 2 |
| Name20| 1 | A | 3 | 1 |Name20| 1 | A | 3 | 2 |
哪里
- Nam1= Name in Semester 1
- CRDT1= Credit in Semester 1
- GRD1= Grade in Semester 1
- Year1= Year in Semester 1
- Semer1 = Semester in Semester 1
- Nam2= Name in Semester 2
- CRDT2= Credit in Semester 2
- GRD2= Grade in Semester 2
- Year2= Year in Semester 2
- Semer2 = Semester in Semester 2
请访问此网址以测试此SQL：http://sqlfiddle.com/#!3/196c6/1
如何创建SQL来生成这样的输出？
答案 0 :(得分：3)
select
s1.Name as nam1, s1.credit as crdt1, s1.Year as year1, s1.semester as semer1,
s2.Name as nam2, s2.credit as crdt2, s2.Year as year2, s2.semester as semer2
from
(select *, ROW_NUMBER() over (partition by year order by name) rn from myTable where semester=1 ) s1
full outer join
(select *, ROW_NUMBER() over (partition by year order by name) rn from myTable where semester=2 ) s2
on s1.year = s2.year
and s1.rn = s2.rn
答案 1 :(得分：1)
当一个简单的分组足够时，我不喜欢做外连接：
select max(case when semester = 1 then Name end) as name1,
max(case when semester = 1 then credit end) as credit1,
max(case when semester = 1 then year end) as year1,
max(case when semester = 1 then semester end) as semester1,
max(case when semester = 2 then Name end) as name2,
max(case when semester = 2 then credit end) as credit2,
max(case when semester = 2 then year end) as year2,
max(case when semester = 2 then semester end) as semester2
from (select t.*,
row_number() over (partition by semester order by name) as rownum
from t
) t2
group by rownum
order by rownum
答案 2 :(得分：0)
select Name,credit, grade, year,semester from myTable
group by semester,year, Name,credit, grade;
现在我们必须使用此前一个查询进行动态查询： 创建为临时表，因为首先有semster 动态创建一个包含循环中所有学期表的所有字段的选择查询： foreach临时表在select查询中连接此表的所有字段 并添加具有此表的学期值的构造标签字段 并添加带联合的临时表
'select'+＃tbls1.fieldName +'，'+ ... + +＃tbls2.fieldName +