那些遇到过的问题

重复键的Mysql group_concat和1个查询中多列重复的计数(查询优化)

use*_*224 5 mysql sql join mariadb

这个问题是关于查询优化,以避免通过PHP多次调用数据库.

所以这是场景,我有两个表,其中包含您可以将其称为参考表的信息,另一个是数据表,字段key1并且key2在两个表中都是通用的,基于这些字段,我们可以加入它们.

我不知道查询是否可以比我现在正在做的更简单,我想要实现的如下:

我希望找到key1,key2,info1,info2与main_info 表不同的,每当串行值小于10并且key1,key2两个表匹配时,然后将它们info1,info2分组,而分组计数key1,key2重复的info1,info2字段和group_concat那些键的重复

表的内容 main_info 

MariaDB [demos]> select * from main_info;
+------+------+-------+-------+----------+
| key1 | key2 | info1 | info2 | date     |
+------+------+-------+-------+----------+
|    1 |    1 |    15 |    90 | 20120501 |
|    1 |    2 |    14 |    92 | 20120601 |
|    1 |    3 |    15 |    82 | 20120801 |
|    1 |    4 |    15 |    82 | 20120801 |
|    1 |    5 |    15 |    82 | 20120802 |
|    2 |    1 |    17 |    90 | 20130302 |
|    2 |    2 |    17 |    90 | 20130302 |
|    2 |    3 |    17 |    90 | 20130302 |
|    2 |    4 |    16 |    88 | 20130601 |
+------+------+-------+-------+----------+
9 rows in set (0.00 sec)
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表的内容 product1

MariaDB [demos]> select * from product1;
+------+------+--------+--------------+
| key1 | key2 | serial | product_data |
+------+------+--------+--------------+
|    1 |    1 |      0 | NaN          |
|    1 |    1 |      1 | NaN          |
|    1 |    1 |      2 | NaN          |
|    1 |    1 |      3 | NaN          |
|    1 |    2 |      0 | 12.556       |
|    1 |    2 |      1 | 13.335       |
|    1 |    3 |      1 | NaN          |
|    1 |    3 |      2 | 13.556       |
|    1 |    3 |      3 | 14.556       |
|    1 |    4 |      3 | NaN          |
|    1 |    5 |      3 | NaN          |
|    2 |    1 |      0 | 12.556       |
|    2 |    1 |      1 | 13.553       |
|    2 |    1 |      2 | NaN          |
|    2 |    2 |     12 | 129          |
|    2 |    3 |     22 | NaN          |
+------+------+--------+--------------+
16 rows in set (0.00 sec)
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通过PHP我在表的当前上下文中对表字段info1和info2表进行分组,多次一个接一个(这里我运行查询两次,你可以看到)main_infoserialproduct_dataproduct1

对于字段serial- 第一个查询

MariaDB [demos]> select * , count(*) as serial_count,GROUP_CONCAT(key1,' ',key2) as serial_ids from 
    -> (
    -> SELECT distinct 
    -> if(b.serial  < 10,a.key1,null) AS `key1`,
    -> if(b.serial  < 10,a.key2,null) AS `key2`,
    -> if(b.serial  < 10,a.info1,null) AS `info1`, 
    ->         if(b.serial  < 10,a.info2,null) AS `info2`
    -> FROM main_info a inner join product1 b on  a.key1 = b.key1 AND a.key2= b.key2
    -> ) as sub group by info1,info2
    -> ;
+------+------+-------+-------+--------------+-------------+
| key1 | key2 | info1 | info2 | serial_count | serial_ids  |
+------+------+-------+-------+--------------+-------------+
| NULL | NULL |  NULL |  NULL |            1 | NULL        |
|    1 |    2 |    14 |    92 |            1 | 1 2         |
|    1 |    3 |    15 |    82 |            3 | 1 3,1 4,1 5 |
|    1 |    1 |    15 |    90 |            1 | 1 1         |
|    2 |    1 |    17 |    90 |            1 | 2 1         |
+------+------+-------+-------+--------------+-------------+
5 rows in set (0.00 sec)
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对于字段product_data- 第二个查询

MariaDB [demos]> select * , count(*) as product_data_count,GROUP_CONCAT(key1,' ',key2) as product_data_ids from 
    -> (
    -> SELECT distinct 
    -> if(b.product_data IS NOT NULL,a.key1,null) AS `key1`,
    -> if(b.product_data IS NOT NULL,a.key2,null) AS `key2`,
    -> if(b.product_data IS NOT NULL,a.info1,null) AS `info1`, 
    ->         if(b.product_data IS NOT NULL,a.info2,null) AS `info2`
    -> FROM main_info a inner join product1 b on  a.key1 = b.key1 AND a.key2= b.key2
    -> ) as sub group by info1,info2
    -> ;
+------+------+-------+-------+--------------------+------------------+
| key1 | key2 | info1 | info2 | product_data_count | product_data_ids |
+------+------+-------+-------+--------------------+------------------+
|    1 |    2 |    14 |    92 |                  1 | 1 2              |
|    1 |    3 |    15 |    82 |                  3 | 1 3,1 4,1 5      |
|    1 |    1 |    15 |    90 |                  1 | 1 1              |
|    2 |    2 |    17 |    90 |                  3 | 2 2,2 3,2 1      |
+------+------+-------+-------+--------------------+------------------+
4 rows in set (0.01 sec)
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我希望使用一个查询得到这样的输出,分组为info1,info2

+------+------+-------+-------+--------------+-------------+--------------------+------------------+
| key1 | key2 | info1 | info2 | serial_count | serial_ids  | product_data_count | product_data_ids |
+------+------+-------+-------+--------------+-------------+--------------------+------------------+
| NULL | NULL |  NULL |  NULL |            1 | NULL        |               NULL | NULL             |
|    1 |    2 |    14 |    92 |            1 | 1 2         |                  1 | 1 2              |
|    1 |    3 |    15 |    82 |            3 | 1 3,1 4,1 5 |                  3 | 1 3,1 4,1 5      |
|    1 |    1 |    15 |    90 |            1 | 1 1         |                  1 | 1 1              |
|    2 |    1 |    17 |    90 |            1 | 2 1         |                  3 | 2 2,2 3,2 1      |
+------+------+-------+-------+--------------+-------------+--------------------+------------------+
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下面是表格的结构

DROP TABLE IF EXISTS `main_info`;
CREATE TABLE `main_info` (
  `key1` int(11) NOT NULL,
  `key2` int(11) NOT NULL,
  `info1` int(11) NOT NULL,
  `info2` int(11) NOT NULL,
  `date` int(11) NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1;


LOCK TABLES `main_info` WRITE;
INSERT INTO `main_info` VALUES (1,1,15,90,20120501),(1,2,14,92,20120601),(1,3,15,82,20120801),(1,4,15,82,20120801),(1,5,15,82,20120802),(2,1,17,90,20130302),(2,2,17,90,20130302),(2,3,17,90,20130302),(2,4,16,88,20130601);
UNLOCK TABLES;


DROP TABLE IF EXISTS `product1`;
CREATE TABLE `product1` (
  `key1` int(11) NOT NULL,
  `key2` int(11) NOT NULL,
  `serial` int(11) NOT NULL,
  `product_data` varchar(1000) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1;


LOCK TABLES `product1` WRITE;
INSERT INTO `product1` VALUES (1,1,0,'NaN'),(1,1,1,'NaN'),(1,1,2,'NaN'),(1,1,3,'NaN'),(1,2,0,'12.556'),(1,2,1,'13.335'),(1,3,1,'NaN'),(1,3,2,'13.556'),(1,3,3,'14.556'),(1,4,3,'NaN'),(1,5,3,'NaN'),(2,1,0,'12.556'),(2,1,1,'13.553'),(2,1,2,'NaN'),(2,2,12,'129'),(2,3,22,'NaN');
UNLOCK TABLES;
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有人请帮助我在一个查询中得到结果.

Sus*_*ilo 2

试试这个

SELECT 
     key1, key2, info1, info2, 
     SUM(Scount) AS serial_count, GROUP_CONCAT(Skey1, ' ', Skey2) AS serial_ids,
     SUM(Pcount) AS product_data_count, GROUP_CONCAT(Pkey1, ' ', Pkey2) AS product_data_ids 
FROM 
(

   SELECT DISTINCT 
     IF(b.serial  < 10 OR b.product_data IS NOT NULL,a.key1, NULL) AS `key1`,
     IF(b.serial  < 10 OR b.product_data IS NOT NULL,a.key2, NULL) AS `key2`,
     IF(b.serial  < 10 OR b.product_data IS NOT NULL,a.info1, NULL) AS `info1`, 
     IF(b.serial  < 10 OR b.product_data IS NOT NULL,a.info2, NULL) AS `info2`,
     IF(b.serial  < 10,a.key1, NULL) AS `Skey1`,
     IF(b.serial  < 10,a.key2, NULL) AS `Skey2`,
     IF(b.product_data IS NOT NULL,a.key1, NULL) AS `Pkey1`,
     IF(b.product_data IS NOT NULL,a.key2, NULL) AS `Pkey2`,
     IF(b.serial < 10, 1, NULL) AS `Scount`,
     IF(b.product_data IS NOT NULL, 1, NULL) AS `Pcount`
   FROM main_info a INNER JOIN product1 b ON  a.key1 = b.key1 AND a.key2= b.key2

   UNION ALL

   SELECT DISTINCT
     NULL AS `key1`,
     NULL AS `key2`,
     NULL AS `info1`,
     NULL AS `info2`,
     NULL AS `Skey1`,
     NULL AS `Skey2`,
     NULL AS `Pkey1`,
     NULL AS `Pkey2`,
     IF(serial > 9, 1, NULL) AS `Scount`,
     IF(product_data IS NULL, 1, NULL) AS `Pcount`
   FROM product1 WHERE serial > 9 xor product_data IS NULL

) AS sub GROUP BY info1,info2
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结果（问题数据）

+------+------+-------+-------+--------------+-------------+--------------------+------------------+
| key1 | key2 | info1 | info2 | serial_count | serial_ids  | product_data_count | product_data_ids |
+------+------+-------+-------+--------------+-------------+--------------------+------------------+
| NULL | NULL | NULL  | NULL  | 1            | NULL        | NULL               | NULL             |
+------+------+-------+-------+--------------+-------------+--------------------+------------------+
| 1    | 2    | 14    | 92    | 1            | 1 2         | 1                  | 1 2              |
+------+------+-------+-------+--------------+-------------+--------------------+------------------+
| 1    | 3    | 15    | 82    | 3            | 1 3,1 4,1 5 | 3                  | 1 3,1 4,1 5      |
+------+------+-------+-------+--------------+-------------+--------------------+------------------+
| 1    | 1    | 15    | 90    | 1            | 1 1         | 1                  | 1 1              |
+------+------+-------+-------+--------------+-------------+--------------------+------------------+
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结果（数据来自评论）

+------+------+-------+-------+--------------+-------------+--------------------+------------------+
| key1 | key2 | info1 | info2 | serial_count | serial_ids  | product_data_count | product_data_ids |
+------+------+-------+-------+--------------+-------------+--------------------+------------------+
| NULL | NULL | NULL  | NULL  | 1            | NULL        | 1                  | NULL             |
+------+------+-------+-------+--------------+-------------+--------------------+------------------+
| 1    | 2    | 14    | 92    | 1            | 1 2         | 1                  | 1 2              |
+------+------+-------+-------+--------------+-------------+--------------------+------------------+
| 1    | 3    | 15    | 82    | 3            | 1 3,1 4,1 5 | 3                  | 1 3,1 4,1 5      |
+------+------+-------+-------+--------------+-------------+--------------------+------------------+
| 1    | 1    | 15    | 90    | 1            | 1 1         | 1                  | 1 1              |
+------+------+-------+-------+--------------+-------------+--------------------+------------------+
| 2    | 4    | 16    | 88    | 1            | 2 4         | 1                  | 2 4              |
+------+------+-------+-------+--------------+-------------+--------------------+------------------+
| 2    | 1    | 17    | 90    | NULL         | NULL        | 3                  | 2 1,2 2,2 3      |
+------+------+-------+-------+--------------+-------------+--------------------+------------------+
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笔记：

我确实能理解问题背后的基本逻辑，所以主要根据预期结果来回答。例如，如果组字段 (info1和info2) 为 null，则其他结果将始终为 null，除了serial_count和product_data_count可以为 1 或 null，您真的想得到这个吗？请注意，这个答案使用另一个子查询来UNION ALL满足这一点。

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