Directly reads a CSV file into DuckDB, tries to detect and create the correct schema for it. This usually is much faster than reading the data into R and writing it to DuckDB.
Usage
duckdb_read_csv(
conn,
name,
files,
...,
header = TRUE,
na.strings = "",
nrow.check = 500,
delim = ",",
quote = "\"",
col.names = NULL,
lower.case.names = FALSE,
sep = delim,
transaction = TRUE,
temporary = FALSE
)Arguments
- conn
A DuckDB connection, created by
dbConnect().- name
The name for the virtual table that is registered or unregistered
- files
One or more CSV file names, should all have the same structure though
- ...
Reserved for future extensions, must be empty.
- header
Whether or not the CSV files have a separate header in the first line
- na.strings
Which strings in the CSV files should be considered to be NULL
- nrow.check
How many rows should be read from the CSV file to figure out data types
- delim
Which field separator should be used
- quote
Which quote character is used for columns in the CSV file
- col.names
Override the detected or generated column names
- lower.case.names
Transform column names to lower case
- sep
Alias for delim for compatibility
- transaction
Should a transaction be used for the entire operation
- temporary
Set to
TRUEto create a temporary table
Examples
if (FALSE) { # duckdb:::TEST_RE2
con <- dbConnect(duckdb())
data <- data.frame(a = 1:3, b = letters[1:3])
path <- tempfile(fileext = ".csv")
write.csv(data, path, row.names = FALSE)
duckdb_read_csv(con, "data", path)
dbReadTable(con, "data")
dbDisconnect(con)
}