如何将子组转置或旋转到一行中？
How do I transpose or pivot subgroups into to a single row?
我有一个 group-by-top-n-results 查询，显示在示例输入数据中。子组（按 ID 分组）限于前 10 个结果，并按 ASC 按 rank 排序。如何从输入示例转到输出示例？
我在想它可能是某种 pivot 函数或 crosstab 解决方案，或者它可能需要自己加入.我只是不确定如何进行这项工作。这几乎就像我们将每个子组连接在它自己的行上一样。
每个子组最多可以有 10 个顶级结果，但也可能没有完整的 10 个。在示例中，子组 1003 & 1007 分别没有超过前 6 名和超过前 3 名的结果.示例输出中的架构是我正在寻找的，将 10 个可能排名靠前的行的所有字段作为列。
示例输入数据
+------+------+----------------------+---------+---------+-------+---------+---------+
| rank | ID | NAME | FIELD 1 | FIELD 2 | MAIN | FIELD 3 | FIELD 4 |
+------+------+----------------------+---------+---------+-------+---------+---------+
| 1 | 1001 | Backdash | 123053 | 2 | 21.1 | 17.09 | 20 |
| 2 | 1001 | cold Stone Creamery | 115404 | 2 | 19.78 | 1.04 | 0.93 |
| 3 | 1001 | Mado | 97650 | 2 | 16.74 | 0.1 | 0.14 |
| 4 | 1001 | Friendly's | 57638 | 1 | 9.88 | 0.21 | 0.4 |
| 5 | 1001 | Fosters Freeze | 53187 | 2 | 9.12 | 0.24 | 1 |
| 6 | 1001 | Marble Slab Creamery | 51381 | 2 | 8.81 | 15.75 | 28.57 |
| 7 | 1001 | Lappert's | 35929 | 1 | 6.16 | 0.01 | 0.04 |
| 8 | 1001 | Greater's | 23050 | 1 | 3.95 | 0.01 | 0.05 |
| 9 | 1001 | Happy Joe's | 20422 | 1 | 3.5 | 12.73 | 25 |
| 10 | 1001 | Shake Shack | 4260 | 1 | 0.73 | 8.1 | 50 |
| 1 | 1003 | Mauds Ice Cream | 949152 | 11 | 22.29 | 0.98 | 0.75 |
| 2 | 1003 | Mr Whippy | 433590 | 5 | 10.18 | 0.61 | 0.78 |
| 3 | 1003 | New Zeland Natural | 411348 | 7 | 9.66 | 0.03 | 0.12 |
| 4 | 1003 | Tropical Sno | 394558 | 10 | 9.27 | 0.15 | 0.4 |
| 5 | 1003 | Culver's | 375755 | 5 | 8.82 | 3.47 | 2.96 |
| 6 | 1003 | Marble Slab Creamery | 276971 | 7 | 6.5 | 13.05 | 12.07 |
| 1 | 1007 | Greater's | 105866 | 2 | 58.96 | 19.91 | 12.5 |
| 2 | 1007 | Hagan-Daz | 37697 | 3 | 20.99 | 26.17 | 37.5 |
| 3 | 1007 | cold Stone Creamery | 25520 | 1 | 14.21 | 0.23 | 0.47 |
+------+------+----------------------+---------+---------+-------+---------+---------+
示例输出格式
+------+-----------------+---------------+----------------+-------------+----------------+-----------------+---------------------+----------------+----------------+-------------+----------------+-----------------+---------------------+----------------+----------------+-------------+----------------+-----------------+--------------+----------------+----------------+-------------+----------------+-----------------+----------------+----------------+----------------+-------------+----------------+-----------------+----------------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+--------------+-----------------+-----------------+--------------+-----------------+------------------+
| ID | TOP 1 NAME | TOP 1 FIELD 1 | TOP 1 FIELD 2 | TOP 1 MAIN | TOP 1 FIELD 3 | TOP 1 FIELD 4 | TOP 2 NAME | TOP 2 FIELD 1 | TOP 2 FIELD 2 | TOP 2 MAIN | TOP 2 FIELD 3 | TOP 2 FIELD 4 | TOP 3 NAME | TOP 3 FIELD 1 | TOP 3 FIELD 2 | TOP 3 MAIN | TOP 3 FIELD 3 | TOP 3 FIELD 4 | TOP 4 NAME | TOP 4 FIELD 1 | TOP 4 FIELD 2 | TOP 4 MAIN | TOP 4 FIELD 3 | TOP 4 FIELD 4 | TOP 5 NAME | TOP 5 FIELD 1 | TOP 5 FIELD 2 | TOP 5 MAIN | TOP 5 FIELD 3 | TOP 5 FIELD 4 | TOP 6 NAME | TOP 6 FIELD 1 | TOP 6 FIELD 2 | TOP 6 MAIN | TOP 6 FIELD 3 | TOP 6 FIELD 4 | TOP 7 NAME | TOP 7 FIELD 1 | TOP 7 FIELD 2 | TOP 7 MAIN | TOP 7 FIELD 3 | TOP 7 FIELD 4 | TOP 8 NAME | TOP 8 FIELD 1 | TOP 8 FIELD 2 | TOP 8 MAIN | TOP 8 FIELD 3 | TOP 8 FIELD 4 | TOP 9 NAME | TOP 9 FIELD 1 | TOP 9 FIELD 2 | TOP 9 MAIN | TOP 9 FIELD 3 | TOP 9 FIELD 4 | TOP 10 NAME | TOP 10 FIELD 1 | TOP 10 FIELD 2 | TOP 10 MAIN | TOP 10 FIELD 3 | TOP 10 FIELD 4 |
+------+-----------------+---------------+----------------+-------------+----------------+-----------------+---------------------+----------------+----------------+-------------+----------------+-----------------+---------------------+----------------+----------------+-------------+----------------+-----------------+--------------+----------------+----------------+-------------+----------------+-----------------+----------------+----------------+----------------+-------------+----------------+-----------------+----------------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+--------------+-----------------+-----------------+--------------+-----------------+------------------+
| 1001 | Backdash | 123053 | 2 | 21.1 | 17.09 | 20 | cold Stone Creamery | 115404 | 2 | 19.78 | 1.04 | 0.93 | Mado | 97650 | 2 | 16.74 | 0.1 | 0.14 | Friendly's | 57638 | 1 | 9.88 | 0.21 | 0.4 | Fosters Freeze | 53187 | 2 | 9.12 | 0.24 | 1 | Marble Slab Creamery | 51381 | 2 | 8.81 | 15.75 | 28.57 | Lappert's | 35929 | 1 | 6.16 | 0.01 | 0.04 | Greater's | 23050 | 1 | 3.95 | 0.01 | 0.05 | Happy Joe's | 20422 | 1 | 3.5 | 12.73 | 25 | Shake Shack | 4260 | 1 | 0.73 | 8.1 | 50 |
| 1003 | Mauds Ice Cream | 949152 | 11 | 22.29 | 0.98 | 0.75 | Mr Whippy | 433590 | 5 | 10.18 | 0.61 | 0.78 | New Zeland Natural | 411348 | 7 | 9.66 | 0.03 | 0.12 | Tropical Sno | 394558 | 10 | 9.27 | 0.15 | 0.4 | Culver's | 375755 | 5 | 8.82 | 3.47 | 2.96 | Marble Slab Creamery | 276971 | 7 | 6.5 | 13.05 | 12.07 | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| 1007 | Greater's | 105866 | 2 | 58.96 | 19.91 | 12.5 | Hagan-Daz | 37697 | 3 | 20.99 | 26.17 | 37.5 | cold Stone Creamery | 25520 | 1 | 14.21 | 0.23 | 0.47 | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
+------+-----------------+---------------+----------------+-------------+----------------+-----------------+---------------------+----------------+----------------+-------------+----------------+-----------------+---------------------+----------------+----------------+-------------+----------------+-----------------+--------------+----------------+----------------+-------------+----------------+-----------------+----------------+----------------+----------------+-------------+----------------+-----------------+----------------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+--------------+-----------------+-----------------+--------------+-----------------+------------------+
PS.
我有编码思维，有一段时间没写了SQL。在 sudocode 中，这可以通过简单的嵌套 for 循环来解决。例如
foreach subgroup i
foreach rank j <= 10
print i, rank[j].name, rank[j].FIELD 1, rank[j].FIELD 2, rank[j].MAIN, rank[j].FIELD 3, rank[j].FIELD 4
print \r\n
您可以使用条件聚合：
select id,
max(case when rank = 1 then name end) as name_1,
max(case when rank = 1 then field1 end) as field1_1,
. . .
max(case when rank = 2 then name end) as name_2,
max(case when rank = 2 then field1 end) as field1_2,
. . .
max(case when rank = 10 then field3 end) as field3_10,
max(case when rank = 10 then field4 end) as field4_10
from inputdata id
group by id;
我有一个 group-by-top-n-results 查询，显示在示例输入数据中。子组（按 ID 分组）限于前 10 个结果，并按 ASC 按 rank 排序。如何从输入示例转到输出示例？
我在想它可能是某种 pivot 函数或 crosstab 解决方案，或者它可能需要自己加入.我只是不确定如何进行这项工作。这几乎就像我们将每个子组连接在它自己的行上一样。
每个子组最多可以有 10 个顶级结果，但也可能没有完整的 10 个。在示例中，子组 1003 & 1007 分别没有超过前 6 名和超过前 3 名的结果.示例输出中的架构是我正在寻找的，将 10 个可能排名靠前的行的所有字段作为列。
示例输入数据
+------+------+----------------------+---------+---------+-------+---------+---------+
| rank | ID | NAME | FIELD 1 | FIELD 2 | MAIN | FIELD 3 | FIELD 4 |
+------+------+----------------------+---------+---------+-------+---------+---------+
| 1 | 1001 | Backdash | 123053 | 2 | 21.1 | 17.09 | 20 |
| 2 | 1001 | cold Stone Creamery | 115404 | 2 | 19.78 | 1.04 | 0.93 |
| 3 | 1001 | Mado | 97650 | 2 | 16.74 | 0.1 | 0.14 |
| 4 | 1001 | Friendly's | 57638 | 1 | 9.88 | 0.21 | 0.4 |
| 5 | 1001 | Fosters Freeze | 53187 | 2 | 9.12 | 0.24 | 1 |
| 6 | 1001 | Marble Slab Creamery | 51381 | 2 | 8.81 | 15.75 | 28.57 |
| 7 | 1001 | Lappert's | 35929 | 1 | 6.16 | 0.01 | 0.04 |
| 8 | 1001 | Greater's | 23050 | 1 | 3.95 | 0.01 | 0.05 |
| 9 | 1001 | Happy Joe's | 20422 | 1 | 3.5 | 12.73 | 25 |
| 10 | 1001 | Shake Shack | 4260 | 1 | 0.73 | 8.1 | 50 |
| 1 | 1003 | Mauds Ice Cream | 949152 | 11 | 22.29 | 0.98 | 0.75 |
| 2 | 1003 | Mr Whippy | 433590 | 5 | 10.18 | 0.61 | 0.78 |
| 3 | 1003 | New Zeland Natural | 411348 | 7 | 9.66 | 0.03 | 0.12 |
| 4 | 1003 | Tropical Sno | 394558 | 10 | 9.27 | 0.15 | 0.4 |
| 5 | 1003 | Culver's | 375755 | 5 | 8.82 | 3.47 | 2.96 |
| 6 | 1003 | Marble Slab Creamery | 276971 | 7 | 6.5 | 13.05 | 12.07 |
| 1 | 1007 | Greater's | 105866 | 2 | 58.96 | 19.91 | 12.5 |
| 2 | 1007 | Hagan-Daz | 37697 | 3 | 20.99 | 26.17 | 37.5 |
| 3 | 1007 | cold Stone Creamery | 25520 | 1 | 14.21 | 0.23 | 0.47 |
+------+------+----------------------+---------+---------+-------+---------+---------+
示例输出格式
+------+-----------------+---------------+----------------+-------------+----------------+-----------------+---------------------+----------------+----------------+-------------+----------------+-----------------+---------------------+----------------+----------------+-------------+----------------+-----------------+--------------+----------------+----------------+-------------+----------------+-----------------+----------------+----------------+----------------+-------------+----------------+-----------------+----------------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+--------------+-----------------+-----------------+--------------+-----------------+------------------+
| ID | TOP 1 NAME | TOP 1 FIELD 1 | TOP 1 FIELD 2 | TOP 1 MAIN | TOP 1 FIELD 3 | TOP 1 FIELD 4 | TOP 2 NAME | TOP 2 FIELD 1 | TOP 2 FIELD 2 | TOP 2 MAIN | TOP 2 FIELD 3 | TOP 2 FIELD 4 | TOP 3 NAME | TOP 3 FIELD 1 | TOP 3 FIELD 2 | TOP 3 MAIN | TOP 3 FIELD 3 | TOP 3 FIELD 4 | TOP 4 NAME | TOP 4 FIELD 1 | TOP 4 FIELD 2 | TOP 4 MAIN | TOP 4 FIELD 3 | TOP 4 FIELD 4 | TOP 5 NAME | TOP 5 FIELD 1 | TOP 5 FIELD 2 | TOP 5 MAIN | TOP 5 FIELD 3 | TOP 5 FIELD 4 | TOP 6 NAME | TOP 6 FIELD 1 | TOP 6 FIELD 2 | TOP 6 MAIN | TOP 6 FIELD 3 | TOP 6 FIELD 4 | TOP 7 NAME | TOP 7 FIELD 1 | TOP 7 FIELD 2 | TOP 7 MAIN | TOP 7 FIELD 3 | TOP 7 FIELD 4 | TOP 8 NAME | TOP 8 FIELD 1 | TOP 8 FIELD 2 | TOP 8 MAIN | TOP 8 FIELD 3 | TOP 8 FIELD 4 | TOP 9 NAME | TOP 9 FIELD 1 | TOP 9 FIELD 2 | TOP 9 MAIN | TOP 9 FIELD 3 | TOP 9 FIELD 4 | TOP 10 NAME | TOP 10 FIELD 1 | TOP 10 FIELD 2 | TOP 10 MAIN | TOP 10 FIELD 3 | TOP 10 FIELD 4 |
+------+-----------------+---------------+----------------+-------------+----------------+-----------------+---------------------+----------------+----------------+-------------+----------------+-----------------+---------------------+----------------+----------------+-------------+----------------+-----------------+--------------+----------------+----------------+-------------+----------------+-----------------+----------------+----------------+----------------+-------------+----------------+-----------------+----------------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+--------------+-----------------+-----------------+--------------+-----------------+------------------+
| 1001 | Backdash | 123053 | 2 | 21.1 | 17.09 | 20 | cold Stone Creamery | 115404 | 2 | 19.78 | 1.04 | 0.93 | Mado | 97650 | 2 | 16.74 | 0.1 | 0.14 | Friendly's | 57638 | 1 | 9.88 | 0.21 | 0.4 | Fosters Freeze | 53187 | 2 | 9.12 | 0.24 | 1 | Marble Slab Creamery | 51381 | 2 | 8.81 | 15.75 | 28.57 | Lappert's | 35929 | 1 | 6.16 | 0.01 | 0.04 | Greater's | 23050 | 1 | 3.95 | 0.01 | 0.05 | Happy Joe's | 20422 | 1 | 3.5 | 12.73 | 25 | Shake Shack | 4260 | 1 | 0.73 | 8.1 | 50 |
| 1003 | Mauds Ice Cream | 949152 | 11 | 22.29 | 0.98 | 0.75 | Mr Whippy | 433590 | 5 | 10.18 | 0.61 | 0.78 | New Zeland Natural | 411348 | 7 | 9.66 | 0.03 | 0.12 | Tropical Sno | 394558 | 10 | 9.27 | 0.15 | 0.4 | Culver's | 375755 | 5 | 8.82 | 3.47 | 2.96 | Marble Slab Creamery | 276971 | 7 | 6.5 | 13.05 | 12.07 | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| 1007 | Greater's | 105866 | 2 | 58.96 | 19.91 | 12.5 | Hagan-Daz | 37697 | 3 | 20.99 | 26.17 | 37.5 | cold Stone Creamery | 25520 | 1 | 14.21 | 0.23 | 0.47 | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
+------+-----------------+---------------+----------------+-------------+----------------+-----------------+---------------------+----------------+----------------+-------------+----------------+-----------------+---------------------+----------------+----------------+-------------+----------------+-----------------+--------------+----------------+----------------+-------------+----------------+-----------------+----------------+----------------+----------------+-------------+----------------+-----------------+----------------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+-------------+----------------+----------------+-------------+----------------+-----------------+--------------+-----------------+-----------------+--------------+-----------------+------------------+
PS.
我有编码思维，有一段时间没写了SQL。在 sudocode 中，这可以通过简单的嵌套 for 循环来解决。例如
foreach subgroup i
foreach rank j <= 10
print i, rank[j].name, rank[j].FIELD 1, rank[j].FIELD 2, rank[j].MAIN, rank[j].FIELD 3, rank[j].FIELD 4
print \r\n
您可以使用条件聚合：
select id,
max(case when rank = 1 then name end) as name_1,
max(case when rank = 1 then field1 end) as field1_1,
. . .
max(case when rank = 2 then name end) as name_2,
max(case when rank = 2 then field1 end) as field1_2,
. . .
max(case when rank = 10 then field3 end) as field3_10,
max(case when rank = 10 then field4 end) as field4_10
from inputdata id
group by id;