Question

假设我有表人物：

<div class="procedure-table">
    <table class="table" style="border: 2px slide;">
        <thead>
            <tr>
                <th>Procedure Name</th>
                <th>Cost</th>
                <th>Taxes</th>
                <th>Notes</th>
            </tr>
        </thead>
        <tbody>
            <tr>
                <td class="proce-td">
                    <ul>
                        <li>
                            <p>Lorem Ipsum is simply dummy text of the printing and typesetting ghj industry.<span><a href="">[+]</a></span>
                            </p>
                        </li>
                    </ul>
                </td>
                <td class="cost-td">Lorem Ipsum is simply dummy text of the printing and typesetting industry.</td>
                <td class="taxes-td">Lorem Ipsum is simply dummy text of the printing and typesetting industry.</td>
                <td>
                    <div class="note-div">Lorem Ipsum is simply dummy text of the printing and typesetting industry.</div>
                    <i class="material-icons close-icon2">close</i>
                    <i class="material-icons edit-icon">edit</i>
                </td>
            </tr>
        </tbody>
    </table>
</div>

表格组：

name | group
------------
bob  | -
bill | -
joe  | -
tim  | -
mei  | -
jen  | -
ben  | -
lyn  | -
eli  | -
fin  | -
hal  | -
kim  | -

如何编写一个从People表返回行的查询，每行按顺序分配给一个组，直到分配了所有10个人。

分配给组的人数不能超过该组的max_people值。因此，如果已达到所有组的最大值，则应保留未分配的剩余人员。

所以输出应该如下：

group | max_people
------------------
A     | 2
B     | 5
C     | 3

非常感谢！

Answer 1

在人员表上创建一个游标 DECLARE @name VARCHAR（50），@ groupname varchar（10） DECLARE people_cursor CURSOR FOR SELECT名称来自人民打开people_cursor FETCH NEXT FROM people_cursor INTO @name WHILE @@ FETCH_STATUS = 0 开始从group table中选择top 1 @groupname = group，其中max_people> 0 更新人员设置组= @groupname其中name = @name 更新组设置max_people = max_people -1其中group = @groupname FETCH NEXT FROM people_cursor INTO @name 结束关闭people_cursor DEALLOCATE people_cursor

Answer 2

首先，您可以根据max_people列的值复制组，如下所示

WITH Repeater (Repeat ) AS (
    SELECT 1 AS Repeat UNION ALL
    SELECT Repeat + 1 FROM Repeater WHERE Repeat < 99
),
GroupsRepeat AS (
    SELECT [group], max_people,  ROW_NUMBER() OVER(ORDER BY [group] ASC) AS row_num
    FROM  Groups INNER JOIN Repeater ON Groups.max_people >= Repeater.Repeat    
)

然后，您可以将定义的GroupsRepeat表与People表连接，如下所示

SELECT People.name, 
          COALESCE(GroupsRepeat.[group], People.[group]) AS [group] 
   FROM   (SELECT *, 
                  ROW_NUMBER() OVER(ORDER BY [group]) AS row_num 
           FROM   People) People 
          LEFT JOIN GroupsRepeat 
                 ON GroupsRepeat.row_num = People.row_num;

您可以看到演示here

Answer 3

为您的姓名编号，例如

select name, row_number() over (order by name) as num
from names

为您的群组指定号码范围：

select 
  grp, 
  sum(max_people) over (order by grp) - max_people + 1 as from_num,
  sum(max_people) over (order by grp) as till_num
from groups

结合两者：

select n.name, g.grp
from
(
  select name, row_number() over (order by name) as num
  from names
) n
left join 
(
  select 
    grp, 
    sum(max_people) over (order by grp) - max_people + 1 as from_num,
    sum(max_people) over (order by grp) as till_num
  from groups
) g on n.num between g.from_num and g.till_num;

SQL - 根据另一个表将表中的行分配到不均匀的组中

3 个答案: