X-Git-Url: https://git.openstreetmap.org./nominatim.git/blobdiff_plain/9cfd891fb981a2a4241e24c4f3c4b5519eceda48..80f7392fb1eff5c6b26e5f85b6873bb133576275:/lib/DB.php

diff --git a/lib/DB.php b/lib/DB.php
index ddc0932c..6307d6ca 100644
--- a/lib/DB.php
+++ b/lib/DB.php
@@ -135,7 +135,7 @@ class DB
         try {
             $stmt = $this->getQueryStatement($sSQL, $aInputVars, $sErrMessage);
 
-            while ($val = $stmt->fetchColumn(0)) { // returns first column or false
+            while (($val = $stmt->fetchColumn(0)) !== false) { // returns first column or false
                 $aVals[] = $val;
             }
         } catch (\PDOException $e) {
@@ -240,6 +240,76 @@ class DB
         return ($this->getOne($sSQL, array(':tablename' => $sTableName)) == 1);
     }
 
+    /**
+    * Check if an index exists in the database. Optional filtered by tablename
+    *
+    * @param string  $sTableName
+    *
+    * @return boolean
+    */
+    public function indexExists($sIndexName, $sTableName = null)
+    {
+        return in_array($sIndexName, $this->getListOfIndices($sTableName));
+    }
+
+    /**
+    * Returns a list of index names in the database, optional filtered by tablename
+    *
+    * @param string  $sTableName
+    *
+    * @return array
+    */
+    public function getListOfIndices($sTableName = null)
+    {
+        //  table_name            | index_name                      | column_name
+        // -----------------------+---------------------------------+--------------
+        //  country_name          | idx_country_name_country_code   | country_code
+        //  country_osm_grid      | idx_country_osm_grid_geometry   | geometry
+        //  import_polygon_delete | idx_import_polygon_delete_osmid | osm_id
+        //  import_polygon_delete | idx_import_polygon_delete_osmid | osm_type
+        //  import_polygon_error  | idx_import_polygon_error_osmid  | osm_id
+        //  import_polygon_error  | idx_import_polygon_error_osmid  | osm_type
+        $sSql = <<< END
+SELECT
+    t.relname as table_name,
+    i.relname as index_name,
+    a.attname as column_name
+FROM
+    pg_class t,
+    pg_class i,
+    pg_index ix,
+    pg_attribute a
+WHERE
+    t.oid = ix.indrelid
+    and i.oid = ix.indexrelid
+    and a.attrelid = t.oid
+    and a.attnum = ANY(ix.indkey)
+    and t.relkind = 'r'
+    and i.relname NOT LIKE 'pg_%'
+    FILTERS
+ ORDER BY
+    t.relname,
+    i.relname,
+    a.attname
+END;
+
+        $aRows = null;
+        if ($sTableName) {
+            $sSql = str_replace('FILTERS', 'and t.relname = :tablename', $sSql);
+            $aRows = $this->getAll($sSql, array(':tablename' => $sTableName));
+        } else {
+            $sSql = str_replace('FILTERS', '', $sSql);
+            $aRows = $this->getAll($sSql);
+        }
+
+        $aIndexNames = array_unique(array_map(function ($aRow) {
+            return $aRow['index_name'];
+        }, $aRows));
+        sort($aIndexNames);
+
+        return $aIndexNames;
+    }
+
     /**
      * Since the DSN includes the database name, checks if the connection works.
      *