我该怎么写这个SQL

Question

使用Firebird 3.0我有这些表

model_types表有一些类型，如Type1，type2，type3 ......我需要得到这样的结果：

Type     All    UFZ   Tempered
=================================
Type1     45     23      12
Type2     0      0       0
Type3     2      0       0

所以我写了这个SQL：

select 
    sum((window.win_width * window.win_height) / 144),
    model_types.model_type_description
from model_types
   left outer join models on (model_types.model_type_id = models.model_type_id)
   inner join series_model on (models.model_id = series_model.model_id)
   inner join window on (series_model.sm_id = window.sm_id)
 where (quote_id = 122) and (window.ufz = 0) and (window.tempered = 0)
 group by model_types.model_type_description

这个SQL只给我的问题＆＃34; type1＆＃34;如果其他类型为零，那么我如何列出model_types表中的所有类型，即使它们是零？

另一个问题：在这个SQL中where条件：

(window.ufz = 0) and (window.tempered = 0)

代表＆＃34; All＆＃34;获得UFZ时我需要使用这些条件：

(window.ufz = 1) and (window.tempered = 0)

并获得Tempered我需要使用这个条件：

(window.ufz = 0) and (window.tempered = 1)

那么我如何在单独的列中显示所有3个结果（All，UFZ，Tempered）？

Answer 1

经过多次测试后，我发现我可以使用Case，但不知道我的SQL是否正确，如果它们是零则不会显示所有模型类型。

select 
    sum(CASE WHEN (window.ufz = 0) and (window.tempered = 0)
      THEN ((window.win_width * window.win_height) / 144) END) AS models_all,

    sum(CASE WHEN (window.ufz = 1) and (window.tempered = 0)
      THEN ((window.win_width * window.win_height) / 144) END) AS models_ufz,

    sum(CASE WHEN (window.ufz = 0) and (window.tempered = 1)
      THEN ((window.win_width * window.win_height) / 144) END) AS models_temp,

    model_types.model_type_description
from model_types
   left outer join models on (model_types.model_type_id = models.model_type_id)
   inner join series_model on (models.model_id = series_model.model_id)
   inner join window on (series_model.sm_id = window.sm_id)
 where (quote_id = 122)
 group by model_types.model_type_description

Answer 2

CASE构造具有ELSE部分，如果您的WHEN部分未经验证，则可以在其中添加默认值。我认为这将完成查询结果中丢失的数据。