我需要使用 Ecto 进行此 SQL 查询:
SELECT users.*, (select count(0) from money_transactions where from_id = users.id AND created_at > '2016-1-25 0:00:00.000000') as money_transactions_today_db FROM "users" WHERE "users"."client_token" = '123'
我尝试做这样的事情,但它不起作用:
query = from users in Like4uElixir.User,
where: users.client_token in ^tokens,
select: {users, (from money_transactions in Like4uElixir.MoneyTransaction,
where: money_transactions.from_id == users.id,
select: count(0))}
Ecto 是否支持子查询?如果没有,我该如何执行查询?
最佳答案
您可以使用查询片段:
query = from users in Like4uElixir.User,
where: users.client_token in ^tokens,
select: {users, (fragment("(SELECT COUNT(0) FROM money_transactions
WHERE money_transactions.from_id == ?)", users.id))}
尽管在这种情况下,查询也可以使用常规连接和 group_by 编写。当前对 Ecto 中子查询的支持是有限的。
关于phoenix-framework - Ecto 模型 - 选择中的子查询,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/35000859/