在tsql

Question

所以我有一个包含以下列的表：

Type    Test    Min     Max
-----------------------------
  1     a        1       2
  1     b       Null    Null
  2     a        0      Null
  2     b       Null     1

试图让所有人都像这样

Type   Test1  Test1 min  Test1max  Test2 Test2min Test2max
------------------------------------------------------------
 1      a       1           2       b     Null       Null
 2      a       0         Null      b     Null        1

在我使用数据透视表之前首先尝试使用unpivot，但它仍然提供重复测试并删除null任何帮助都非常感谢 还需要显示空值

Select type, result
(
From 
Select type, min
From table t
)
Unpivot
(result for minmax in (min1)
)

选择 感谢

Answer 1

使用row_number()和条件聚合：

select 
    [Type]
  , Test_1     = max(case when rn = 1 then Test end)
  , Test_1_Min = max(case when rn = 1 then Min  end)
  , Test_1_Max = max(case when rn = 1 then Max  end)
  , Test_2     = max(case when rn = 2 then Test end)
  , Test_2_Min = max(case when rn = 2 then Min  end)
  , Test_2_Max = max(case when rn = 2 then Max  end)
from (
  select *
    , rn = row_number() over (partition by [Type] order by [Test]) 
  from t
  ) as s
group by s.Type 

rextester演示：http://rextester.com/BKL48976

返回：

+------+--------+------------+------------+--------+------------+------------+
| Type | Test_1 | Test_1_Min | Test_1_Max | Test_2 | Test_2_Min | Test_2_Max |
+------+--------+------------+------------+--------+------------+------------+
|    1 | a      |          1 | 2          | b      | NULL       | NULL       |
|    2 | a      |          0 | NULL       | b      | NULL       | 1          |
+------+--------+------------+------------+--------+------------+------------+

Answer 2

select *
from table t1
join table t2 
  on t1.type = t2.type 
 and t1.test < t2.test