SQL - 在具有许多条件的每个列之间打印许多单词

Question

好的,首先我有不可变的值:

4   8   16   32   64   128   256

我有一张这样的表:

+----+------+---------------------+-------------+
| id |   full_name  |  club_name  |  y_of_birth |
+----+------+---------------------+-------------+
| 1  | Ahmed Sayed  |   El Ahly   |    2000     |
+----+------+---------------------+-------------+
| 2  | Kareem Gaber |   El Ahly   |    2000     |
+----+------+---------------------+-------------+
| 3  | Maher Zein   |   El Ahly   |    2003     |
+----+------+---------------------+-------------+
| 4  | Mohab Saeed  |   El Ahly   |    2003     |
+----+------+---------------------+-------------+
| 5  | Kamal saber  |   wadi dgla |    2000     |
+----+------+---------------------+-------------+
| 6  | gamel kamel  |   el-nasr   |    2002     |
+----+------+---------------------+-------------+
| 7  | omar galal   |   Cocorico  |    2000     |
+----+------+---------------------+-------------+
| 8  | Kamal saber  |   Cocorico  |    2004     |
+----+------+---------------------+-------------+
| 9  | Mohamed gad  |   Ismaily   |    2000     |  
+----+------+---------------------+-------------+
| 10 | ehab zeyad   |   Ismaily   |    2005     |
+----+------+---------------------+-------------+
| 11 | moaz maged   |   Smouha    |    2001     |
+----+------+---------------------+-------------+
| 12 | mazen mahmod |   elmasry   |    2006     |
+----+------+---------------------+-------------+
| 13 | ahmed shawky |   Petroget  |    2002     |
+----+------+---------------------+-------------+
| 14 | shaker ali   |   Petroget  |    2007     |
+----+------+---------------------+-------------+

我试图用查询过滤数据库中的数据

select full_name,club_name from players where y_of_birth=2000

结果是5玩家应该是这样的:

+--------------+--------------+
|   full_name  |  club_name   |
+--------------+--------------+
| Ahmed Sayed  |   El Ahly    |
+----+------+--+--------------+
| Kareem Gaber |   El Ahly    |
+------+-------+--------------+
| Kamal saber  |  wadi dgla   |
+------+-------+--------------+
| omar galal   |   Cocorico   |
+------+-------+--------------+
| Mohamed gad  |  Ismaily     |
+------+-------+--------------+

好的条件是:

如果结果大于 4 > 4且小于 8 <= 8则将结果放入8我们的情况下结果是5它意味着8 - 5 = 3 平均迭代这个单词3次结果应该是这样的:

+--------------+-------------+
|   full_name  |  club_name  |
+--------------+-------------+
| Ahmed Sayed  |  El Ahly    |
+----+------+--+-------------+
| **ANY WORD** |             |
+--------------+-------------+
| Kareem Gaber |  El Ahly    |
+------+-------+-------------+
| Kamal saber  |  wadi dgla  |
+------+-------+-------------+
| **ANY WORD** |             |
+--------------+-------------+ 
| omar galal   |  Cocorico   |
+------+-------+-------------+
| Mohamed gad  |  Ismaily    |
+------+-------+-------------+
| **ANY WORD** |             |
+--------------+-------------+

注意:请不要在**ANY WORD**上面的示例之间相邻:

+------+-------+
| **ANY WORD** |
+--------------+
| **ANY WORD** |
+--------------+

要么

club_name以上示例之间没有相邻:

+------+-------+
|    El Ahly   |
+--------------+
|    El Ahly   |
+--------------+

更新 :

另一个例子

它基于这些数字

4 8 16 32 64 128 256

和条件是:

1. 如果查询结果 <= 4和> 2则表示(4 - the number of query result)

例如:如果查询结果是3如此4 - 3 = 1,从而1是一个数字的**ANY WORD**,从而所希望的输出将是这样的:

+--------------+-------------+
|   full_name  |  club_name  |
+--------------+-------------+
| Ahmed Sayed  |  El Ahly    |
+----+------+--+-------------+
| **ANY WORD** |             |
+--------------+-------------+
| Kareem Gaber |  El Ahly    |
+------+-------+-------------+
| Kamal saber  |  wadi dgla  |
+--------------+-------------+

2. 另一个示例与8 如果查询结果 <= 8和> 4意思(8 - the number of query result)

例如:在查询结果是5如此8 - 5 = 3,从而3是一个数字的**ANY WORD**,从而所希望的输出将是这样的

+--------------+-------------+
|   full_name  |  club_name  |
+--------------+-------------+
| Ahmed Sayed  |  El Ahly    |
+----+------+--+-------------+
| **ANY WORD** |             |
+--------------+-------------+
| Kareem Gaber |  El Ahly    |
+------+-------+-------------+
| Kamal saber  |  wadi dgla  |
+------+-------+-------------+
| **ANY WORD** |             |
+--------------+-------------+ 
| omar galal   |  Cocorico   |
+------+-------+-------------+
| Mohamed gad  |  Ismaily    |
+------+-------+-------------+
| **ANY WORD** |             |
+--------------+-------------+

等有4和16和32和64...等,直到256.

任何帮助将非常感激 .

Answer 1

新的和改进的（版本3如何）使用变量并使用与这里基本相同的技巧：

SELECT
  IF(is_real, '**ANY WORD**', full_name) AS full_name,
  IF(is_real, '', club_name) AS club_name
FROM
  (
    SELECT
      full_name,
      club_name,
      (@row_num2:= @row_num2 + 1) AS row_num
    FROM
      (
        SELECT p3.*
        FROM
          (
        SELECT
          p2.*,
          (@row_num := @row_num + 1) AS row_num
        FROM
          (
            SELECT *
            FROM players AS p1
            WHERE y_of_birth = 2000
          ) AS p2
        CROSS JOIN
          (
            SELECT
              @row_num := 0,
              @count := (SELECT COUNT(*) FROM players WHERE y_of_birth = 2000)
          ) AS vars
        ORDER BY club_name
      ) AS p3
    ORDER BY row_num % FLOOR(@row_num / 2), row_num
  ) AS p4
CROSS JOIN
  (
    SELECT
      @row_num2 := -1,
      @extra := GREATEST(2, POW(2, CEIL(LOG2(@count)))) - @count) AS vars
  ) AS data
LEFT JOIN
  (
    (SELECT 1 AS is_real)
    UNION ALL
    (SELECT 0 AS is_real)
  ) AS filler
ON
  MOD(row_num, FLOOR(@count / @extra)) = 0 AND
  row_num / FLOOR(@count / @extra) < @extra
ORDER BY row_num, is_real

对于您提供的示例数据，这会产生类似以下内容的内容：

+--------------+-----------+
| full_name    | club_name |
+--------------+-----------+
| Ahmed Sayed  | El Ahly   |
| **ANY WORD** |           |
| Mohamed gad  | Ismaily   |
| **ANY WORD** |           |
| omar galal   | Cocorico  |
| **ANY WORD** |           |
| Kareem Gaber | El Ahly   |
| Kamal saber  | wadi dgla |
+--------------+-----------+

这应该适用于任何大小的结果；只需将条件 ( y_of_birth = 2000) 更改为您想要的任何条件即可。我升级到 MySQL 5.6 来测试这一点（结果实际上有一点不同）。

1基本技巧是使用 a 创建一个包含静态值（在本例中为 和0）的两行表UNION，然后LEFT JOIN将其多次填充到实际结果中以填充到 2 的幂。这意味着我们已经计算了数字结果中的每一行（称为row_num），以便我们可以正确地制定连接条件。最后，每隔这么多行就会产生一个重复行；最后一点是IF通过检查我们是否位于真行或假行（1或0）来更改我们在这些重复项上选择的内容（使用 s）。

这应该可以防止同一支球队的球员彼此相邻，除非这是不可能的，因为一支球队有太多球员；有关如何执行此操作的更多信息，请参阅上面的链接。基本思想是按俱乐部排序，然后从该列表的前半部分和后半部分交替挑选。

最后一个技巧是找出虚拟行的数量和位置。在尝试了几件事之后，我意识到这实际上非常简单：只需连接每一行，直到我们达到所需的虚拟行数（@extra）。但是，这会将所有虚拟行打包在结果的顶部；为了将它们分散得更多（不是完美地分散，而是更多地分散），计算我们需要添加一个 ( FLOOR(@count / @extra)) 的频率，然后每隔那么多行添加一个（ON条件的第一部分），直到添加了足够的行（条件的第一部分）第二部分）。