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,
  update = driver %in% db_drivers, delete_dsn = FALSE,
  delete_layer = FALSE, fid_column_name = NULL)
# S3 method for data.frame
st_write(obj, dsn, layer = NULL, ...)
write_sf(..., quiet = TRUE, delete_layer = TRUE)
# S4 method for PostgreSQLConnection,character,sf
dbWriteTable(conn, name,
  value, ..., row.names = FALSE, overwrite = FALSE, append = FALSE,
  field.types = NULL, factorsAsCharacter = TRUE, binary = TRUE)
# S4 method for DBIObject,character,sf
dbWriteTable(conn, name, value, ...,
  row.names = FALSE, overwrite = FALSE, append = FALSE,
  field.types = NULL, factorsAsCharacter = TRUE, binary = TRUE)

Arguments

obj

object of class sf or sfc

dsn

data source name (interpretation varies by driver - for some drivers, dsn is a file name, but may also be a folder or contain a database name) or a Database Connection (currently official support is for RPostgreSQL connections)

layer

layer name (varies by driver, may be a file name without extension); 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 http://www.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 objects into character strings (default), else into numbers by as.numeric.

update

logical; FALSE by default for single-layer drivers but TRUE by default for database drivers as defined by db_drivers. For database-type drivers (e.g. GPKG) TRUE values will make GDAL try to update (append to) the existing data source, e.g. adding a table to an existing database.

delete_dsn

logical; delete data source dsn before attempting to write?

delete_layer

logical; delete layer layer before attempting to write? (not yet implemented)

fid_column_name

character, name of column with feature IDs; if specified, this column is no longer written as feature attribute.

conn

DBIObject

name

character vector of names (table names, fields, keywords).

value

a data.frame.

row.names

Add a row.name column, or a vector of length nrow(obj) containing row.names; default FALSE.

overwrite

Will try to drop table before writing; default FALSE.

append

Append rows to existing table; default FALSE.

field.types

default NULL. Allows to override type conversion from R to PostgreSQL. See dbDataType() for details.

binary

Send geometries serialized as Well-Known Binary (WKB); if FALSE, uses Well-Known Text (WKT). Defaults to TRUE (WKB).

Value

obj, invisibly; in case obj is of class sfc, it is returned as an sf object.

Details

columns (variables) of a class not supported are dropped with a warning. When deleting layers or data sources is not successful, no error is emitted. delete_dsn and delete_layers should be handled with care; the former may erase complete directories or databases.

Examples

Run this code

# NOT RUN {
nc = st_read(system.file("shape/nc.shp", package="sf"))
st_write(nc, "nc.shp")
st_write(nc, "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)
st_write(meuse_sf, "meuse.csv", layer_options = "GEOMETRY=AS_XY") # writes X and Y as columns
st_write(meuse_sf, "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"))
# }