58 lines
1.9 KiB
PHP
58 lines
1.9 KiB
PHP
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<?php
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/*
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* Title: PostGIS to GeoJSON
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* Notes: Query a PostGIS table or view and return the results in GeoJSON format, suitable for use in OpenLayers, Leaflet, etc.
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* Author: Bryan R. McBride, GISP
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* Contact: bryanmcbride.com
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* GitHub: https://github.com/bmcbride/PHP-Database-GeoJSON
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*/
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# Connect to PostgreSQL database
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$conn = new PDO('pgsql:host=localhost;dbname=postgisftw','pgis','MYPGISPASSWORD');
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# Build SQL SELECT statement and return the geometry as a GeoJSON element
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$sql = "SELECT *, public.ST_AsGeoJSON(geom) AS geojson FROM countries WHERE continent = 'Europe'";
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/*
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* If bbox variable is set, only return records that are within the bounding box
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* bbox should be a string in the form of 'southwest_lng,southwest_lat,northeast_lng,northeast_lat'
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* Leaflet: map.getBounds().toBBoxString()
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*/
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if (isset($_GET['bbox'])) {
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$bbox = explode(',', $_GET['bbox']);
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$sql = $sql . ' WHERE public.ST_Transform(geom, 4326) && public.ST_SetSRID(public.ST_MakeBox2D(public.ST_Point('.$bbox[0].', '.$bbox[1].'), public.ST_Point('.$bbox[2].', '.$bbox[3].')),4326);';
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}
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# Try query or error
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$rs = $conn->query($sql);
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if (!$rs) {
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echo 'An SQL error occured.\n';
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exit;
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}
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# Build GeoJSON feature collection array
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$geojson = array(
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'type' => 'FeatureCollection',
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'features' => array()
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);
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# Loop through rows to build feature arrays
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while ($row = $rs->fetch(PDO::FETCH_ASSOC)) {
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$properties = $row;
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# Remove geojson and geometry fields from properties
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unset($properties['geojson']);
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unset($properties['geom']);
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$feature = array(
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'type' => 'Feature',
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'geometry' => json_decode($row['geojson'], true),
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'properties' => $properties
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);
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# Add feature arrays to feature collection array
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array_push($geojson['features'], $feature);
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}
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header('Content-type: application/json');
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echo json_encode($geojson, JSON_NUMERIC_CHECK);
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$conn = NULL;
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?>
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