st_write: Write simple features object to file or database

Description Usage Arguments Details Value See Also Examples

View source: R/read.R

Description

Write simple features object to file or database

Usage

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st_write(obj, dsn, layer, ...)

## S3 method for class 'sfc'
st_write(obj, dsn, layer, ...)

## S3 method for class '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 class 'data.frame'
st_write(obj, dsn, layer = NULL, ...)

write_sf(..., quiet = TRUE, append = FALSE, delete_layer = !append)

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/ogr_formats.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

config_options

character, named vector with GDAL config options specified, this column is no longer written as feature attribute.

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.

Value

obj, invisibly

See Also

st_drivers, dbWriteTable

Examples

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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
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
## Not run: 
 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"))

## End(Not run)

sf documentation built on June 10, 2021, 1:06 a.m.