How to use column defaults with dbWriteTable(..., append=TRUE) in RPostgreSQL - r

Question

The dbWriteTable function in RPostgreSQL seems to ignore column names and tries to push data from R to PostgreSQL as-is. This is problematic when appending to existing tables, particularly if there are columns un-specified in the R object that should be given default values.
RMySQL handles this case very gracefully by adding the column names to LOAD DATA LOCAL INFILE. How do I force RPostgreSQL to assign default values to un-specified columns in dbWriteTable when append=TRUE?
Here is an example:
CREATE TABLE test (
column_a varchar(255) not null default 'hello',
column_b integer not null
);
insert into test values (DEFAULT, 1);
Which yields the following table:
select * from test;
column_a | column_b
----------+----------
hello | 1
(1 row)
I want to insert some new data to this table from R:
require('RPostgreSQL')
driver <- PostgreSQL()
con <- dbConnect(driver, host='localhost', dbname='development')
set.seed(42)
x <- data.frame(column_b=sample(1:100, 10))
dbWriteTable(con, name='test', value=x, append=TRUE, row.names=FALSE)
dbDisconnect(con)
But I get the following error:
Error in postgresqlgetResult(new.con) :
RS-DBI driver: (could not Retrieve the result : ERROR: missing data for
column "column_b"
CONTEXT: COPY test, line 1: "92"
)
This is because I have not specified the column_a field, so dbWriteTable is trying to write the data for column_b into column_a. I would like to force dbWriteTable to use the defaults for column_a, and properly write column_b to column_b.
I should only get a failure if:
I fail to specify a column with no default value
I try to insert a column that doesn't exist in the table
I insert the wrong datatype into an existing column

Answer 1

I had exactly the same problem, this fixed it.
Check out the dbWriteTable2 function from package caroline.
The code then allows you to write a data frame without an id column into the database using add_id = TRUE, e.g.
dbWriteTable2(con_psql,"domains",data_domains,append=TRUE,overwrite=FALSE,row.names=FALSE,add.id=TRUE)