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postgreSQL独占排序_Sql_Postgresql - Fatal编程技术网

postgreSQL独占排序

postgreSQL独占排序,sql,postgresql,Sql,Postgresql,可能只需要离开问题一分钟,但这给了我一些麻烦 编写一个查询,返回10到50之间的所有用户id记录的计数,不包括用户id 20和30 到目前为止,我已经知道了这一点,而且很接近,但我不记得如何单独排序 SELECT COUNT (user_id) FROM purchases WHERE user_id BETWEEN 10 AND 50; 单向: SELECT COUNT (user_id) FROM purchases WHERE user_id BETWEEN 10 AND 50 and

可能只需要离开问题一分钟,但这给了我一些麻烦

编写一个查询,返回10到50之间的所有用户id记录的计数,不包括用户id 20和30

到目前为止,我已经知道了这一点,而且很接近,但我不记得如何单独排序

SELECT COUNT (user_id)
FROM purchases
WHERE user_id BETWEEN 10 AND 50;
单向:

SELECT COUNT (user_id)
FROM purchases
WHERE user_id BETWEEN 10 AND 50
and user_id not in (20, 30)
单向:

SELECT COUNT (user_id)
FROM purchases
WHERE user_id BETWEEN 10 AND 50
and user_id not in (20, 30)