按字符类型左联接R [英] Left join in R by character type

问题描述

我试图从2个不同的网站上抓取电影背景

am trying to scrape movie sets from 2 different websites

我想结合这两个信息，并使用电影标题名称将它们捆绑在一起.这是第一个数据集看起来像

And I want to combine these 2 informations, and tied them up using the movie title name. Here is the first dataset looks like

structure(list(event_name = c("maze runner: the death cure", "star wars: the last jedi", 
"spider-man: homecoming"), event_start_time = structure(c(100, 
200, 300), class = "Date"), movie_sold_all = c(100L, 200L, 
300L)), .Names = c("event_name", "event_start_time", "movie_sold_all"
), row.names = c(NA, 3L), class = "data.frame")

这是我抓到的第二个数据集

And this is the 2nd dataset that i've scraped

我必须上传图片，因为有> 10列

I have to upload image only since there are >10 columns

我希望拥有的是加入movie_title，因此他们将合并这2条信息.基本上类似于SQL中的left join

What i expect to have is to join the movie_title so they it'll incorporate these 2 informations. Basically similar like left join in SQL

我尝试了merge( df_bq_movies,movies,by.y="movie_title",all.x = TRUE)

但发生错误

Error in merge.data.frame(df_bq_movies, movies, by.y = "movie_title", :'by.x' and 'by.y' specify different numbers of columns

有关更多信息，这是数据集的维度

For more information, this is the dimension of the dataset

data 1 : 605 rows , 3 column data 2 : 509 rows , 21 column

data 1 : 605 rows , 3 column data 2 : 509 rows , 21 column

推荐答案

使用合并，必须定义by.x和by.y，如果两个数据集上的列名相同，则只能使用by.

With merge you have to define both by.x and by.y if the column name is the same on both datasets you can just use by instead.

例如

 merge( df_bq_movies, movies, by.x = "event_name", by.y = "movie_title")

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