Question

请一些帮助来获取mysql中的列数...我不知道如何编写以下问题的查询。

我正在使用以下查询

 https://www.elastic.co/guide/en/elasticsearch/client/java-api/current/and-filter.html

并且此查询的输出显示如下（只是示例中的coloumn名称将更改）

SELECT * FROM
              (
               SELECT cont_details.*, 
               location.location,
               depot_details.depot_name as depot_name, 
               depot_details.depot_code as depot_code,
               block.block_id,
               depot_details.depot_city,

               depot_tracking.depot_tracking_id as depot_tracking_id

               FROM depot_tracking

               LEFT JOIN depot_details
               ON depot_tracking.depot_details_id = depot_details.depot_details_id

               LEFT JOIN cont_details 
               ON depot_tracking.cont_details_id = cont_details.cont_details_id

               LEFT JOIN block 
               ON depot_tracking.cont_details_id = block.cont_details_id    

               LEFT JOIN cont_sold
               ON depot_tracking.cont_details_id = cont_sold.cont_details_id

               LEFT JOIN location
               ON depot_details.depot_city = location.port_code

               WHERE 
               depot_tracking.status = "0" 
               AND depot_tracking.gate_out =""
               AND block.block_id IS NULL
               AND cont_sold.cont_sold_id IS NULL

               ORDER BY
               cont_details.cont_details_id ASC,
               str_to_date(depot_tracking.gate_in,"%d-%m-%Y") DESC
              )
        origin GROUP BY origin.cont_details_id

现在从这张表中我需要根据位置，大小和类型颜色获得不同的位置和数量。示例如下所示。

 ------------------------------------------
  location   |   size   |  type |   price | 
 -------------------------------------------
   USA     |    20    |   GP   |    230   |
   USA     |    20    |   GP   |    330   | 
   UAE     |    40    |   HD   |    230   | 
   IND     |    40    |   RF   |    230   | 
   IND     |    30    |   FR   |    430   | 
   IND     |    40    |   FR   |    870   | 
   USA     |    30    |   HD   |    230   | 
   UAE     |    40    |   RF   |    430   |
   USA     |    30    |   GP   |    230   | 
   UAE     |    20    |   HD   |    445   | 
   UAE     |    20    |   RF   |    323   | 
   IND     |    30    |   FR   |    130   | 
-------------------------------------------

请有人帮助我获取上面的表输出以及如何进行查询。谢谢。

Answer 1

您可以使用以下方法将数据从表格转换为第二张表格 -

SELECT location, 
SUM(CASE WHEN size=20 AND `type`='GP' THEN COUNT(location) ELSE NULL END) AS '20GP', 
SUM(CASE WHEN size=20 AND `type`='HD' THEN COUNT(location) ELSE NULL END) AS '20HD', 
SUM(CASE WHEN size=20 AND `type`='RF' THEN COUNT(location) ELSE NULL END) AS '20RF' 
FROM mytable 
GROUP BY location, size, `type`;

Answer 2

SELECT 
Mtab.location,
SUM(CASE WHEN ( Mtab.size='20' AND Mtab.type='GP') THEN 1 ELSE 0 END) AS '20GP', 
SUM(CASE WHEN ( Mtab.size='20' AND Mtab.type='HS') THEN 1 ELSE 0 END) AS '20GP', 
SUM(CASE WHEN ( Mtab.size='20' AND Mtab.type='RF') THEN 1 ELSE 0 END) AS '20GP', 
(
  your current query...
  your current query...
  your current query...
)
Mtab
GROUP BY Mtab.location

如何获取MySQL中的DISTINCT列和COUNT列（MySql PIVOT表）？

2 个答案: