Spatial join for dbSpatial objects

Performs a spatial join between two dbSpatial objects using a specified spatial predicate function.

Usage

# S3 method for class 'dbSpatial'
st_join(x, y, join = st_intersects, suffix = c(".x", ".y"), ...)

Arguments

x

A dbSpatial object.

y

A dbSpatial object.

join

Spatial predicate function to use for the join. Default is st_intersects. Supported predicates: st_intersects, st_contains, st_within, st_covers, st_covered_by, st_crosses, st_disjoint, st_equals, st_touches, st_overlaps.

suffix

Character vector of length 2. Suffixes to add to duplicate column names from x and y. Default is c(".x", ".y").

...

Additional arguments passed to the internal join function.

Value

A dbSpatial object containing the spatial join result.

Details

This function follows the sf pattern where spatial predicates are passed as the join argument.

Examples

if (interactive() && requireNamespace("duckdb", quietly = TRUE)) {
  con <- DBI::dbConnect(duckdb::duckdb(), ":memory:")
  DBI::dbExecute(con, "SET threads = 1")

  df1 <- data.frame(id = 1:3, x = c(0, 10, 20), y = c(0, 10, 20))
  pts1 <- dbSpatial(conn = con, name = "pts1", value = df1,
                    x_colName = "x", y_colName = "y", overwrite = TRUE)

  df2 <- data.frame(id = 4:6, x = c(0, 15, 25), y = c(0, 15, 25))
  pts2 <- dbSpatial(conn = con, name = "pts2", value = df2,
                    x_colName = "x", y_colName = "y", overwrite = TRUE)

  # Spatial join using intersection
  result <- sf::st_join(pts1, pts2, join = sf::st_intersects)

  # Spatial join using within predicate
  result <- sf::st_join(pts1, pts2, join = sf::st_within)

  DBI::dbDisconnect(con, shutdown = TRUE)
}