RPostgreSQL - import dataframe into a table

Question

I want to export a complete dataframe into a table which is already created in a database(postgresql) and contains the similar data.

I found few questions explaining about dbwrite table (....overwrite = TRUE), i don't want to overwrite the data which is already present in my table. i just want to update my table with the dataframe from r console.

can someone let me know how can i do this..

something like this

dbInsertTable(con, df, tablename = "MyTable")

Answer 1

You'll need dbWriteTable

Assuming you don't use row names in your data frame you'd do

dbWriteTable(con, "MyTable", df, row.names=FALSE, append=TRUE)

if you want your row names from the df to be a column in your database table then you'd set that option to TRUE. If your table is in a schema other than the public schema then you'd do c('myschema', 'MyTable') instead of the intuitive 'myschema.MyTable'. Also, the columns of your dataframe need to be in the same order as the columns in your database's table. It matches based on order not name.

As an aside, you probably shouldn't use capital letters in your postgres table or column names because then you need to quote them. If you're really using capital letters then you'd need something like dbWriteTable(con, '"MyTable"', df, row.names=FALSE, append=TRUE)