MySQL解析函数

Question

我有一个table格式如下

SurveyCity ProductName SurveybyCompany1 SurveybyCompany2
City1      Chocolate     Good           Good
City1      Caramel       Good           Bad
City1      Vanilla       Bad            Good
City1      Butterscoth   Bad            Bad
City2      Chocolate     Good           Good
City2      Caramel       Good           Bad
City2      Vanilla       Bad            Good
City2      Butterscoth   Bad            Bad

我想要这样的报告

Company1    Company2    Caramel Chocolate Vanilla Butterscoth   
Good        Good        0          2        0       0
Good        Bad         2          0        0       0
Bad         Good        0          0        2       0
Bad         Bad         0          0        0       2

我正在编写如下 4 个查询来生成此报告

select productname,count(*) from table where surveybycompany1='Good' and surveybycompany2='Good' group by productname

我的疑问是，是否可以在一个查询中生成整个输出 table。我正在使用 MySQL DB

请提出您宝贵的建议

Answer 1

您可以使用 sum、if 和 group by

select SurveybyCompany1 Company1, 
SurveybyCompany2 Company2, 
sum(if(ProductName = 'Caramel', 1, 0)) as Caramel, 
sum(if(ProductName = 'Chocolate', 1, 0)) as Chocolate, 
sum(if(ProductName = 'Vanilla', 1, 0)) Vanilla, 
sum(if(ProductName = 'Butterscoth', 1, 0)) Butterschoth 
from your_table group by Company1, Company2
order by Company1 desc, Company2 desc;

输出：

+----------+----------+---------+-----------+---------+--------------+
| Company1 | Company2 | Caramel | Chocolate | Vanilla | Butterschoth |
+----------+----------+---------+-----------+---------+--------------+
| Good     | Good     |       0 |         2 |       0 |            0 |
| Good     | Bad      |       2 |         0 |       0 |            0 |
| Bad      | Good     |       0 |         0 |       2 |            0 |
| Bad      | Bad      |       0 |         0 |       0 |            2 |
+----------+----------+---------+-----------+---------+--------------+

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