Question

我有一个我想要捕获的SQL查询。这是查询：

sl = SlocMetric.find_by_sql("select sum(code_added), 
     sum(comments_added), sum(blanks_added), sum(code_removed), 
     sum(comments_removed), sum(blanks_removed) from sloc_metrics
       inner join diffs on diffs.id = sloc_metrics.diff_id 
       inner join commits on commits.id = diffs.commit_id 
    where commits.id = '499848202'")

这个查询在实际SQL中的输出会给我一个包含四个和值的表，如下所示：

sum| sum| sum| sum|
1     23   43   34

有没有办法可以捕获这些值而无需使用ActiveRecord。我知道有一个.sum方法但是为了使用它，我必须在ActiveRecord中真正修改查询和/或使用我真的不想使用的Arel。帮助将不胜感激。谢谢。

Answer 1

您可以使用ActiveRecord::Base.connection.select_rows()，它会返回一个数组数组，其中每一行都由一个具有SELECT值的数组表示。例如，在您的情况下，您将执行：

sl = ActiveRecord::Base.connection.select_rows("select sum(code_added), 
     sum(comments_added), sum(blanks_added), sum(code_removed), 
     sum(comments_removed), sum(blanks_removed) from sloc_metrics
       inner join diffs on diffs.id = sloc_metrics.diff_id 
       inner join commits on commits.id = diffs.commit_id 
    where commits.id = '499848202'")

输出将是：

#=> [[1, 23, 43, 34]]

现在您可以使用s1[0]访问值，因为您的查询只输出一行：

sl[0].inspect
#=> "[1, 23, 43, 34]"

Answer 2

您可以为每个sum命名，即：

sl = SlocMetric.find_by_sql("select sum(code_added) as sum_1, 
     sum(comments_added) as sum_2, sum(blanks_added) as sum_3, sum(code_removed) as sum_4, 
     sum(comments_removed) as sum_5, sum(blanks_removed) as sum_6 from sloc_metrics
       inner join diffs on diffs.id = sloc_metrics.diff_id 
       inner join commits on commits.id = diffs.commit_id 
    where commits.id = '499848202'")

结果是SlocMetric个对象的数组，然后您应该能够在每个元素中访问它，例如：

sl[0].sum_1

如何将find_by_sql（SUM（字段））的结果存储到变量中？

2 个答案: