Sql rake 文件中的查询未显示结果

Question

我正尝试在 rake 任务中运行这个 SQL 查询，但它确实显示了任何结果。但是我已经在 Dbeaver 中尝试了运行ning 这个查询并且它运行非常好。第一个 puts 只在终端中显示 # 而 second puts 不显示任何值。请帮我找到问题。

namespace :expense do
  desc "send emails"
  task send_reminder: :environment do
  sql = <<-SQL
  SELECT
    c.id             as corporation_id
  , cs_i.id          as issue_id
  , MAX(i.id)        as expense_id
  , MAX(i."date")    as expense_date
  FROM companies c
  JOIN expenses i on i.corporation_id = c.id
  JOIN issues cs_i on i.issue_id = cs_i.id
  WHERE c.amount > 0 and 
        cs_i.amount > 0 and 
        i."date" < (select (current_date at time zone 'UTC' - interval '1 week')) and i.amount_type = 0 
  GROUP BY c.id, cs_i.id
  SQL
    scope = Expense.connection.execute(sql)
      puts "#{scope}"
    scope.each do |expense|
      puts "#{expense}"
    end    
  end
end

Answer 1

如果您尝试运行原始 SQL，您可能不应该使用 connection.execute。请参阅 execute 方法的文档：

Executes the SQL statement in the context of this connection and returns the raw result from the connection adapter. Note: depending on your database connector, the result returned by this method may be manually memory managed. Consider using the exec_query wrapper instead.

execute returns 来自您的连接适配器的原始结果。例如，对于 PostgreSQL 它是 PG::Result 对象。

您可能也不想使用 exec_query，因为它也会 return 某种原始结果。

根据我在您的代码中看到的情况，您可能想使用 find_by_sql。它执行查询和 returns 标准 ActiveRecord 对象：

namespace :expense do
  desc "send emails"
  task send_reminder: :environment do
    sql = <<-SQL
      sql truncated...
    SQL

    scope = Expense.find_by_sql(sql)
      puts "#{scope}"
    scope.each do |expense|
      puts "#{expense}"
    end    
  end
end

Sql rake 文件中的查询未显示结果

Sql Query in rake file not showing result

sql

ruby-on-rails

postgresql

rake