Write simple features object to file or database

Write simple features object to file or database

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 = isFALSE(append),
  fid_column_name = NULL
)

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

write_sf(..., quiet = TRUE, append = FALSE, 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.
append	Append rows to existing table; default FALSE.
delete_dsn	logical; delete data source dsn before attempting to write?
delete_layer	logical; delete layer layer before attempting to write?
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.
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 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.

See also

st_drivers

Examples

nc = st_read(system.file("shape/nc.shp", package="sf"))
#> Reading layer `nc' from data source `/tmp/RtmpCdQsky/temp_libpath64f92385e079/sf/shape/nc.shp' using driver `ESRI Shapefile'
#> Simple feature collection with 100 features and 14 fields
#> geometry type:  MULTIPOLYGON
#> dimension:      XY
#> bbox:           xmin: -84.32385 ymin: 33.88199 xmax: -75.45698 ymax: 36.58965
#> CRS:            4267
st_write(nc, paste0(tempdir(), "/", "nc.shp"))
#> Writing layer `nc' to data source `/tmp/Rtmp0dwyov/nc.shp' using driver `ESRI Shapefile'
#> Writing 100 features with 14 fields and geometry type Multi Polygon.
st_write(nc, paste0(tempdir(), "/", "nc.shp"), delete_layer = TRUE) # overwrites
#> Deleting layer `nc' using driver `ESRI Shapefile'
#> Writing layer `nc' to data source `/tmp/Rtmp0dwyov/nc.shp' using driver `ESRI Shapefile'
#> Writing 100 features with 14 fields and geometry type Multi Polygon.
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")
#> Writing layer `meuse' to data source `/tmp/Rtmp0dwyov/meuse.csv' using driver `CSV'
#> options:        GEOMETRY=AS_XY 
#> Writing 155 features with 12 fields and geometry type Point.
st_write(meuse_sf, paste0(tempdir(), "/", "meuse.csv"), layer_options = "GEOMETRY=AS_WKT",
  delete_dsn=TRUE) # overwrites
#> Deleting source `/tmp/Rtmp0dwyov/meuse.csv' using driver `CSV'
#> Writing layer `meuse' to data source `/tmp/Rtmp0dwyov/meuse.csv' using driver `CSV'
#> options:        GEOMETRY=AS_WKT 
#> Writing 155 features with 12 fields and geometry type Point.
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"))
}