Question

我以前在Python中遇到过相同的问题：Convert Interval Outer Join SQL in Python Pandas Dataframe 我想在R中做到这一点。

我正在将Oracle SQL外部间隔连接转换为R。下面是Oracle SQL：

WITH df_interval AS
          (SELECT '1' id,
                     'AAA' interval,
                     1000 begin,
                     2000 end
              FROM DUAL
            UNION ALL
            SELECT '1' id,
                     'BBB' intrvl,
                     2100 begin,
                     3000 end
              FROM DUAL
            UNION ALL
            SELECT '2' id,
                     'CCC' intrvl,
                     3100 begin,
                     4000 end
              FROM DUAL
            UNION ALL
            SELECT '2' id,
                     'DDD' intrvl,
                     4100 begin,
                     5000 end
              FROM DUAL),
      df_point AS
          (SELECT '1' id, 'X1' point, 1100 mid FROM DUAL
            UNION ALL
            SELECT '1' id, 'X2' point, 2050 mid FROM DUAL
            UNION ALL
            SELECT '1' id, 'X3' point, 3200 mid FROM DUAL
            UNION ALL
            SELECT '2' id, 'X4' point, 4200 mid FROM DUAL
            UNION ALL
            SELECT '2' id, 'X5' point, 5500 mid FROM DUAL)
SELECT pt.id,
         point,
         mid,
         interval
  FROM df_interval it RIGHT OUTER JOIN df_point pt ON pt.id = it.id AND pt.mid BETWEEN it.begin AND it.end

我希望这样的结果：

  ID point   mid interval
0  1    X1  1100      AAA
1  1    X2  2050      NaN
2  1    X3  3200      NaN
3  2    X4  4200      DDD
4  2    X5  5500      NaN

赞赏有人可以帮助我吗？

Answer 1

以下是使用data.table软件包的选项：

library(data.table)
setDT(df_interval)
setDT(df_point)
df_interval[df_point, on=.(id, begin<=mid, end>=mid),
    .(ID=id, point=i.point, mid=i.mid, interval=x.interval)]

输出：

   ID point  mid interval
1:  1    X1 1100      AAA
2:  1    X2 2050     <NA>
3:  1    X3 3200     <NA>
4:  2    X4 4200      DDD
5:  2    X5 5500     <NA>

数据：

df_interval <- data.frame(id=c(1,1,2,2), 
    interval=c('AAA','BBB','CCC','DDD'),
    begin=c(1000,2100,3100,4100),
    end=c(2000,3000,4000,5000))
df_point <- data.frame(id=c(1,1,1,2,2),
    point=c('X1','X2','X3','X4','X5'),
    mid=c(1100,2050,3200,4200,5500))

在R数据框中转换间隔外部联接SQL

1 个答案: