使用MonetDB在R中执行mySQL查询

Question

I am new to SQL and am using MonetDB to load a large file into R studio. I have loaded my data as a db using monetDB, and would now like to execute the R code below on the data in this database:

my_selection <- db_data %>% group_by(id) %>% 
  tally(. , sort = TRUE) %>% 
  top_n(100) %>% 
  select(id) 

Basically, I want to group my data by "id", tally and sort it, and select the 100 largest elements in it. What would be an equivalent of this in SQL?

I am executing queries in the following way in R:

my_selection <- dbGetQuery(connection,"SELECT * FROM my_table [INSERT REST OF CODE HERE]") 

Answer 1

That's depends on the DBMS you're using ,

SQL-Server :

SELECT TOP 100 id,sum(YourOtherColumn) as sum_c
FROM YourTable
GROUP BY id
ORDER BY sum_c DESC

MySQL :

SELECT id,sum(YourOtherColumn) as sum_c
FROM YourTable
GROUP BY id
ORDER BY sum_c DESC
LIMIT 100

If it's something else, tell me and I'll edit the answer.