Ruby中如何用续集gem进行长尾词聚合查询？

2026-04-10 07:211阅读0评论SEO资讯

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可以使用子查询来执行这样的查询：

sqlSELECT (SELECT COUNT(*) FROM users WHERE blah='blah') AS users, (SELECT COUNT(*) FROM contacts WHERE blah='blah') AS contacts;

是否可以使用续集来执行这样的查询：

select (select count(*) from users where blah = 'blah') as "users", (select count(*) from contacts where blah = 'blah') as "contacts"

我知道我可以使用续集一次执行这些查询,但我想同时执行它们.

您可以在不使用以下内容编写原始SQL的情况下执行该查询：

dataset = DB.select {[ DB[:users].where(blah: 'blah').select { count('*') }.as(:users), DB[:contacts].where(blah: 'blah').select { count('*') }.as(:contacts) ]} dataset.first # => { users: X, contacts: Y } dataset.sql # => "SELECT (SELECT count('*') FROM \"users\" WHERE (\"blah\" = 'blah')) AS \"users\", # (SELECT count('*') FROM \"contacts\" WHERE (\"blah\" = 'blah')) AS \"contacts\""

标签：多个聚合查询是否