在子查询中再次过滤

Question

是否有办法从子查询中的选定项再次过滤？

例如：我已经过滤的用户从一个公司：

SELECT * FROM user WHERE companyId = 123 

现在我要过滤的女性，男性和今年从公司上述创建的用户一般。目前我使用此查询：

SELECT 
    (SELECT COUNT(id) FROM user WHERE companyId = 123 && sex = "male") maleUser, 
    (SELECT COUNT(id) FROM user WHERE companyId = 123 && sex = "female") femaleUser, 
    (SELECT COUNT(id) FROM user WHERE companyId = 123 && YEAR(created) = YEAR(NOW())) currentYearUser 

但我想，使其更容易，如：

SELECT 
    (SELECT COUNT(id) FROM userAlreadyFilteredByCompany WHERE sex = "male") maleUser, 
    (SELECT COUNT(id) FROM userAlreadyFilteredByCompany WHERE sex = "female") femaleUser, 
    (SELECT COUNT(id) FROM userAlreadyFilteredByCompany WHERE YEAR(created) = YEAR(NOW())) currentYearUser 

FROM 
    (SELECT id, created FROM user WHERE companyId = 123) userAlreadyFilteredByCompany 

有没有办法做到这一点？我认为在选择已经过滤的结果时，它更易于理解，并且工作量更低。

Answer 1

SELECT 
    SUM(CASE WHEN sex = "male" THEN 1 ELSE 0 END) as maleUser, 
    SUM(CASE WHEN sex = "female" THEN 1 ELSE 0 END) as femaleUser, 
    SUM(CASE WHEN YEAR(created) = YEAR(NOW()) THEN 1 ELSE 0 END) as currentYearUser 

FROM user 
WHERE companyId = 123 

您可以使用CASE/WHEN加入您的情况，总结了数字

Answer 2

试试这个：

SELECT 
    SUM(sex = "male") maleUser, 
    SUM(sex = "female") femaleUser, 
    SUM(YEAR(created) = YEAR(NOW())) currentYearUser 
FROM user WHERE companyId = 123 

Answer 3

嘿，你可以尝试这样的：

SELECT 
    COUNT(if(sex = "male", 1, NULL) as maleUser, 
    COUNT(if(sex = "female", 1, NULL) as femaleUser, 
    COUNT(if(YEAR(created) = YEAR(NOW())), 1, NULL) as currentYearUser 
FROM user 
WHERE companyID = 123