if (FALSE) {
if (requireNamespace("DBI") && requireNamespace("RPostgres")) {
library("DBI")
library("RPostgres")
# Create connection
conn <- tryCatch(dbConnect(RPostgres::Postgres()), error = function(e) e)
if (inherits(conn, "PqConnection")) {
# Create database
dbSendQuery(conn, "CREATE DATABASE postgistest")
# New connection to the created database
conn <- dbConnect(RPostgres::Postgres(), dbname = "postgistest")
# Initialize PostGIS in Postgres
dbSendQuery(conn, "CREATE EXTENSION postgis")
dbSendQuery(conn, "SELECT postgis_full_version()")
# Create table
dbSendQuery(conn, "CREATE TABLE locations(loc_id integer primary key
, loc_name varchar(70), geog geography(POINT) );")
# Insert data
dbSendQuery(conn, "INSERT INTO locations(loc_id, loc_name, geog)
VALUES (1, 'Waltham, MA', ST_GeogFromText('POINT(42.40047 -71.2577)') )
, (2, 'Manchester, NH', ST_GeogFromText('POINT(42.99019 -71.46259)') )
, (3, 'TI Blvd, TX', ST_GeogFromText('POINT(-96.75724 32.90977)') );")
# Get data (notice warnings of unknown field type for geog)
dbGetQuery(conn, "SELECT * from locations")
# Once you're setup, use geojson_read()
conn <- dbConnect(RPostgres::Postgres(), dbname = "postgistest")
state <- "SELECT row_to_json(fc)
FROM (SELECT 'FeatureCollection' As type, array_to_json(array_agg(f)) As features
FROM (SELECT 'Feature' As type
, ST_AsGeoJSON(lg.geog)::json As geometry
, row_to_json((SELECT l FROM (SELECT loc_id, loc_name) As l
)) As properties
FROM locations As lg ) As f ) As fc;"
json <- geojson_read(conn, query = state, what = "json")
## map the geojson with map_leaf()
map_leaf(json)
}
}
}
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