how to create a nested query using sqldf
我正在尝试使用 sqldf 编写嵌套查询。数据集是 \\'contact_fb \\' 。我试图只取行没有 clubmahindra 和列 \\'from_name\\' 中的不同名称，然后左加入 \\'contact_fb \\' 以获取其他列中的所有信息。这不是我想要的结果。
1 | contact_fb =structure(list(X = 1:6, from_name = c("Club Mahindra","Club Mahindra","pinto","valencia","valencia","Club Mahindra"), type = structure(c(2L, 2L, 2L, 1L, 1L, 2L), .Label = c("link","photo","status","video"), class ="factor")), .Names = c("X","from_name","type"), row.names = c(NA, 6L), class ="data.frame") |
我的尝试是
1 | names_cm=sqldf("select t1.from_name, t2.* from (select distinct from_name from contact_fb where from_name!='Club Mahindra') as t1 left join ( select * from contact_fb ) as t2 on t1.from_name=t2.t1.from_name") |
我终于可以通过
得到它
1 | sqldf("select distinct(t1.from_name),t2.* from df t1 left join df t2 on (t1.from_name=t2.from_name) where t1.from_name!='Club Mahindra' group by t1.from_name") |
我不明白我哪里出错了。我还能通过我的方式吗？
输出是
1 2 | 3 Pinto photo 4 valencia link |
问题末尾显示的输出似乎是一组不同的
1 2 3 | sqldf("select distinct from_name, type from contact_fb where from_name != 'Club Mahindra'") |
给予：
1 2 3 | from_name type 1 pinto photo 2 valencia link |