st_write: Write simple features object to file or database

Description

Write simple features object to file or database

Usage

st_write(obj, dsn, layer, ...)
# S3 method for sfc
st_write(obj, dsn, layer, ...)
# S3 method for sf
st_write(
  obj,
  dsn,
  layer = NULL,
  ...,
  driver = guess_driver_can_write(dsn),
  dataset_options = NULL,
  layer_options = NULL,
  quiet = FALSE,
  factorsAsCharacter = TRUE,
  append = NA,
  delete_dsn = FALSE,
  delete_layer = !is.na(append) && !append,
  fid_column_name = NULL,
  config_options = character(0)
)
# S3 method for data.frame
st_write(obj, dsn, layer = NULL, ...)
write_sf(..., quiet = TRUE, append = FALSE, delete_layer = !append)
st_delete(
  dsn,
  layer = character(0),
  driver = guess_driver_can_write(dsn),
  quiet = FALSE
)

Value

obj, invisibly

Arguments

obj: object of class sf or sfc
dsn: data source name. Interpretation varies by driver: can be a filename, a folder, a database name, or a Database Connection (we officially test support for RPostgres::Postgres() connections).
layer: layer name. Varies by driver, may be a file name without extension; for database connection, it is the name of the table. If layer is missing, the basename of dsn is taken.
...: other arguments passed to dbWriteTable when dsn is a Database Connection
driver: character; name of driver to be used; if missing and dsn is not a Database Connection, a driver name is guessed from dsn; st_drivers() returns the drivers that are available with their properties; links to full driver documentation are found at https://gdal.org/drivers/vector/index.html
dataset_options: character; driver dependent dataset creation options; multiple options supported.
layer_options: character; driver dependent layer creation options; multiple options supported.
quiet: logical; suppress info on name, driver, size and spatial reference
factorsAsCharacter: logical; convert factor levels to character strings (TRUE, default), otherwise into numbers when factorsAsCharacter is FALSE. For database connections, factorsAsCharacter is always TRUE.
append: logical; should we append to an existing layer, or replace it? if TRUE append, if FALSE replace. The default for st_write is NA which raises an error if the layer exists. The default for write_sf is FALSE, which overwrites any existing data. See also next two arguments for more control on overwrite behavior.
delete_dsn: logical; delete data source dsn before attempting to write?
delete_layer: logical; delete layer layer before attempting to write? The default for st_write is FALSE which raises an error if the layer exists. The default for write_sf is TRUE.
fid_column_name: character, name of column with feature IDs; if specified, this column is no longer written as feature attribute.
config_options: character, named vector with GDAL config options

Details

Columns (variables) of a class not supported are dropped with a warning.

When updating an existing layer, records are appended to it if the updating object has the right variable names and types. If names don't match an error is raised. If types don't match, behaviour is undefined: GDAL may raise warnings or errors or fail silently.

When deleting layers or data sources is not successful, no error is emitted. delete_dsn and delete_layer should be handled with care; the former may erase complete directories or databases.

st_delete deletes layer(s) in a data source, or a data source if layers are omitted; it returns TRUE on success, FALSE on failure, invisibly.

Examples

Run this code

nc = st_read(system.file("shape/nc.shp", package="sf"))
st_write(nc, paste0(tempdir(), "/", "nc.shp"))
st_write(nc, paste0(tempdir(), "/", "nc.shp"), delete_layer = TRUE) # overwrites
if (require(sp, quietly = TRUE)) {
 data(meuse, package = "sp") # loads data.frame from sp
 meuse_sf = st_as_sf(meuse, coords = c("x", "y"), crs = 28992)
 # writes X and Y as columns:
 st_write(meuse_sf, paste0(tempdir(), "/", "meuse.csv"), layer_options = "GEOMETRY=AS_XY")
 st_write(meuse_sf, paste0(tempdir(), "/", "meuse.csv"), layer_options = "GEOMETRY=AS_WKT",
   delete_dsn=TRUE) # overwrites
if (FALSE) {
 library(sp)
 example(meuse, ask = FALSE, echo = FALSE)
 try(st_write(st_as_sf(meuse), "PG:dbname=postgis", "meuse_sf",
     layer_options = c("OVERWRITE=yes", "LAUNDER=true")))
 demo(nc, ask = FALSE)
 try(st_write(nc, "PG:dbname=postgis", "sids", layer_options = "OVERWRITE=true"))
}
}