我有一张表，列出了购买了每种产品的客户以及购买日期。我有他们买的东西和日期。像这样：
Client | Item | Date
___________________________
John | CD | 2019-09-09
John | LP | 2019-09-08
John | DVD | 2019-09-07
Mary | CD | 2019-09-07
Mary | Book | 2019-09-06
Mary | DVD | 2019-09-05
Louis | CD | 2019-09-06
Louis | LP | 2019-09-06
I am using R. I tried this structure, which is the summarize function:
df %>%
group_by(Date, Item) %>%
mutate(id = paste0("new_col_", row_number())) %>%
ungroup() %>%
spread(id, Client)
But it returned the same client in various line, and I do not want this. I need in one.
I expect something like this:
Client | Book | CD | DVD | LP
_____________________________________________________________________
John | N/A | 2019-09-09 | 2019-09-07 | 2019-09-08
Mary | 2019-09-06 | 2019-09-07 | 2019-09-05 | N/A
Louis | N/A | 2019-09-06 | N/A | 2019-09-06