Question

在向SQL表添加虚拟填充行时，我需要帮助。该表包含带有familyID的家庭卡，但我需要为非家庭的家庭添加填充符

下面是一个示例。我本质上是想添加保留familyID的填充行，以确保每个家族都是4的倍数。

如果这个家庭有3个人，我将添加1个填充物 4人无所事事 5 ppl加3填料 1 ppl加3种填充剂等。

+----------+-----------+----------+
| FamilyID | FirstName | LastName |
+----------+-----------+----------+
| 1234     | Janet     | Roberts  |
+----------+-----------+----------+
| 1234     | Kevin     | Roberts  |
+----------+-----------+----------+
| 1234     | DUMMY     | DUMMY    |
+----------+-----------+----------+
| 1234     | DUMMY     | DUMMY    |
+----------+-----------+----------+
| 3423     | Adam      | Lake     |
+----------+-----------+----------+
| 3423     | DUMMY     | DUMMY    |
+----------+-----------+----------+
| 3423     | DUMMY     | DUMMY    |
+----------+-----------+----------+
| 3423     | DUMMY     | DUMMY    |
+----------+-----------+----------+
| 1111     | April     | Lo       |
+----------+-----------+----------+
| 1111     | Randy     | Lo       |
+----------+-----------+----------+
| 1111     | Abby      | Lo       |
+----------+-----------+----------+
| 1111     | Ray       | Lo       |
+----------+-----------+----------+
| 1111     | Sandra    | Lo       |
+----------+-----------+----------+
| 1111     | DUMMY     | DUMMY    |
+----------+-----------+----------+
| 1111     | DUMMY     | DUMMY    |
+----------+-----------+----------+
| 1111     | DUMMY     | DUMMY    |
+----------+-----------+----------+

Answer 1

我明白了。我不确定您要查询select还是insert。以下生成额外的行：

select familyid, 'DUMMY', 'DUMMY'
from (select familyid, count(*) as cnt
      from t
      group by familyid
     ) t join
     (values (1), (2), (3)) as n(n)
     on (cnt % 4) <= 4 - n.n
where cnt % 4 > 0;

对于select，您可以使用union all：

insert into t(FamilyId, FirstName, LastName)
    select familyid, 'DUMMY', 'DUMMY'
    from (select familyid, count(*) as cnt
          from t
          group by familyid
         ) t join
         (values (1), (2), (3)) as n(n)
         on (cnt % 4) <= 4 - n.n
    where cnt % 4 > 0;

如果familyID不是4的倍数，则在SQL表中创建伪填充行

1 个答案: