带有计数的 SQlite 嵌套查询

Question

我的 Sqlite 数据库中有以下 table :

ID_container : A5, A5, E12, E12, E12
ID_line : A5_1, A5_2, E12_1, E12_2, E12_3
同意：是，是，否，是，否

在我看来，查询涉及 3 种情况：

它计算每个ID_container
它计算每行链接到 ID_container、
它计算每行 "no" 的数量 ID_container,

预期结果是：

ID_container : A5, E12
Number_of_line : 2, 3
Number_of_yes : 2, 1
Number_of_no : 0, 2

我正在处理以下无效的查询：

    SELECT req1.ID_container, req2.Number_of_line, req1.agreement_yes, req3.agreement_no
    FROM 
    (select t_ID_container,COUNT(ID_line) as agreement_yes FROM my_table WHERE agreement='Yes' GROUP BY ID_container) as req1
    INNER JOIN
    (select t_ID_container,COUNT(ID_line) as Number_of_line FROM my_table  GROUP BY ID_container) as req2 
    INNER JOIN
    (select t_ID_container,COUNT(ID_line) as agreement_no FROM my_table  WHERE agreement='No' GROUP BY ID_container) as req3
ON req1.ID_container=req2.ID_container=req3.ID_container

有点迷茫，不知道怎么进步

感谢您的帮助！

Answer 1

您可以使用条件聚合通过一个查询来完成。

SELECT ID_container, 
count(*) as number_of_line,
count(case when agreement='Yes' then 1 end) as number_of_yes,
count(case when agreement='No' then 1 end) as number_of_no
FROM my_table 
GROUP BY ID_container

带有计数的 SQlite 嵌套查询

SQlite nested query with counts

sql

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sqlite

querying

nested-queries