avoid 'SELECT *'

[nominatim.git] / lib / ReverseGeocode.php

diff --git a/lib/ReverseGeocode.php b/lib/ReverseGeocode.php
index a950643f8a0f1e155f11f3036fe18bf82e331945..d06166a5e534f2ce4effe0ca4f7778f5326b5445 100644 (file)
--- a/lib/ReverseGeocode.php
+++ b/lib/ReverseGeocode.php
@@ -75,11 +75,14 @@ class ReverseGeocode
     
     protected function polygonFunctions($sPointSQL, $iMaxRank)
     {
+        // starts the nopolygonFound function if no polygon is found with the lookupPolygon function
         $oResult = null;
         
         $aPlace = $this->lookupPolygon($sPointSQL, $iMaxRank);
         if ($aPlace) {
             $oResult = new Result($aPlace['place_id']);
+        // if no polygon which contains the searchpoint is found,
+        // the noPolygonFound function searches in the country_osm_grid table for a polygon
         } elseif (!$aPlace && $iMaxRank > 4) {
             $aPlace = $this->noPolygonFound($sPointSQL, $iMaxRank);
             if ($aPlace) {
@@ -92,8 +95,9 @@ class ReverseGeocode
     protected function noPolygonFound($sPointSQL, $iMaxRank)
     {
         // searches for polygon in table country_osm_grid which contains the searchpoint
-        $sSQL = 'SELECT * FROM country_osm_grid';
-        $sSQL .= ' WHERE ST_CONTAINS (geometry, '.$sPointSQL.' )';
+        // and searches for the nearest place node to the searchpoint in this polygon
+        $sSQL = 'SELECT country_code FROM country_osm_grid';
+        $sSQL .= ' WHERE ST_CONTAINS (geometry, '.$sPointSQL.') limit 1';
         
         $aPoly = chksql(
             $this->oDB->getRow($sSQL),
@@ -102,15 +106,16 @@ class ReverseGeocode
         if ($aPoly) {
             $sCountryCode = $aPoly['country_code'];
             
-            $sSQL = 'SELECT *, ST_distance('.$sPointSQL.', geometry) as distance';
+            $sSQL = 'SELECT place_id, ST_distance('.$sPointSQL.', geometry) as distance';
             $sSQL .= ' FROM placex';
             $sSQL .= ' WHERE osm_type = \'N\'';
             $sSQL .= ' AND country_code = \''.$sCountryCode.'\'';
             $sSQL .= ' AND rank_address > 0';
-            $sSQL .= ' AND rank_address <= ' .$iMaxRank;
+            $sSQL .= ' AND rank_address <= ' .min(25, $iMaxRank);
             $sSQL .= ' AND type != \'postcode\'';
             $sSQL .= ' AND name IS NOT NULL ';
             $sSQL .= ' and indexed_status = 0 and linked_place_id is null';
+            $sSQL .= ' AND ST_DWithin('.$sPointSQL.', geometry, 1.0)';
             $sSQL .= ' ORDER BY distance ASC, rank_address DESC';
             $sSQL .= ' LIMIT 1';
             
@@ -127,11 +132,16 @@ class ReverseGeocode
     
     protected function lookupPolygon($sPointSQL, $iMaxRank)
     {
-        
+        // searches for polygon where the searchpoint is within
+        // if a polygon is found, placenodes with a higher rank are searched inside the polygon
+    
+        // polygon search begins at suburb-level
         if ($iMaxRank > 25) $iMaxRank = 25;
-        
-        $sSQL = 'SELECT * FROM';
-        $sSQL .= '(select place_id,parent_place_id,rank_address, rank_search, country_code, geometry';
+        // no polygon search over country-level
+        if ($iMaxRank < 4) $iMaxRank = 4;
+        // search for polygon
+        $sSQL = 'SELECT place_id, parent_place_id, rank_address, rank_search FROM';
+        $sSQL .= '(select place_id, parent_place_id, rank_address, rank_search, country_code, geometry';
         $sSQL .= ' FROM placex';
         $sSQL .= ' WHERE ST_GeometryType(geometry) in (\'ST_Polygon\', \'ST_MultiPolygon\')';
         $sSQL .= ' AND rank_address Between 4 AND ' .$iMaxRank;
@@ -148,6 +158,7 @@ class ReverseGeocode
             'Could not determine polygon containing the point.'
         );
         if ($aPoly) {
+        // if a polygon is found, search for placenodes begins ...
             $iParentPlaceID = $aPoly['parent_place_id'];
             $iRankAddress = $aPoly['rank_address'];
             $iRankSearch = $aPoly['rank_search'];
@@ -170,8 +181,8 @@ class ReverseGeocode
                 } elseif ($iMaxRank <= 25) {
                     $fSearchDiam = 0.1;
                 }
-                
-                $sSQL = 'SELECT *';
+
+                $sSQL = 'SELECT place_id';
                 $sSQL .= ' FROM (';
                 $sSQL .= ' SELECT place_id, rank_address,country_code, geometry,';
                 $sSQL .= ' ST_distance('.$sPointSQL.', geometry) as distance';
@@ -223,7 +234,10 @@ class ReverseGeocode
 
     public function lookupPoint($sPointSQL, $bDoInterpolation = true)
     {
-        
+        // starts if the search is on POI or street level,
+        // searches for the nearest POI or street,
+        // if a street is found and a POI is searched for,
+        // the nearest POI which the found street is a parent of is choosen.
         $iMaxRank = $this->iMaxRank;
 
         // Find the nearest point
@@ -320,7 +334,7 @@ class ReverseGeocode
                 
                   // In the US we can check TIGER data for nearest housenumber
                 if (CONST_Use_US_Tiger_Data && $aPlace['country_code'] == 'us' && $this->iMaxRank >= 28) {
-                    $fSearchDiam = $aPlace['rank_search'] > 28 ? $aPlace['distance'] : 0.001;
+                    $fSearchDiam = $aPlace['rank_address'] > 28 ? $aPlace['distance'] : 0.001;
                     $sSQL = 'SELECT place_id,parent_place_id,30 as rank_search,';
                     $sSQL .= 'ST_LineLocatePoint(linegeo,'.$sPointSQL.') as fraction,';
                     $sSQL .= 'ST_distance('.$sPointSQL.', linegeo) as distance,';