diff --git a/core/Driver/SQL/PostgreSQL.class.php b/core/Driver/SQL/PostgreSQL.class.php
index a97aa69..fdc10f3 100644
--- a/core/Driver/SQL/PostgreSQL.class.php
+++ b/core/Driver/SQL/PostgreSQL.class.php
@@ -4,6 +4,7 @@ namespace Driver\SQL;
 
 use \Api\Parameter\Parameter;
 
+use Driver\SQL\Column\Column;
 use \Driver\SQL\Column\IntColumn;
 use \Driver\SQL\Column\SerialColumn;
 use \Driver\SQL\Column\StringColumn;
@@ -12,7 +13,9 @@ use \Driver\SQL\Column\DateTimeColumn;
 use Driver\SQL\Column\BoolColumn;
 use Driver\SQL\Column\JsonColumn;
 
+use Driver\SQL\Expression\Add;
 use Driver\SQL\Strategy\Strategy;
+use Driver\SQL\Strategy\UpdateStrategy;
 
 class PostgreSQL extends SQL {
 
@@ -129,24 +132,31 @@ class PostgreSQL extends SQL {
 
   protected function getOnDuplicateStrategy(?Strategy $strategy, &$params) {
       if (!is_null($strategy)) {
-
-        /*if ($onDuplicateKey instanceof UpdateStrategy) {
+        if ($strategy instanceof UpdateStrategy) {
               $updateValues = array();
-              foreach($onDuplicateKey->getValues() as $key => $value) {
+              foreach($strategy->getValues() as $key => $value) {
+                $leftColumn = $this->columnName($key);
                 if ($value instanceof Column) {
-                  $columnName = $value->getName();
-                  $updateValues[] = "\"$key\"=\"$columnName\"";
+                  $columnName = $this->columnName($value->getName());
+                  $updateValues[] = "$leftColumn=$columnName";
+                } else if ($value instanceof Add) {
+                  $columnName = $this->columnName($value->getColumn());
+                  $operator = $value->getOperator();
+                  $value = $value->getValue();
+                  $updateValues[] = "$leftColumn=$columnName$operator" . $this->addValue($value, $params);
                 } else {
-                  $updateValues[] = "\"$key\"=" . $this->addValue($value, $parameters);
+                  $updateValues[] = "$leftColumn=" . $this->addValue($value, $parameters);
                 }
               }
 
-              $onDuplicateKey = " ON CONFLICT DO UPDATE SET " . implode(",", $updateValues);
-            } else*/ {
-          $strategyClass = get_class($strategy);
-          $this->lastError = "ON DUPLICATE Strategy $strategyClass is not supported yet.";
-          return false;
-        }
+              $conflictingColumns = $this->columnName($strategy->getConflictingColumns());
+              $updateValues = implode(",", $updateValues);
+              return " ON CONFLICT ($conflictingColumns) DO UPDATE SET $updateValues";
+          } else {
+            $strategyClass = get_class($strategy);
+            $this->lastError = "ON DUPLICATE Strategy $strategyClass is not supported yet.";
+           return false;
+          }
       } else {
         return "";
       }
diff --git a/core/Driver/SQL/SQL.class.php b/core/Driver/SQL/SQL.class.php
index 0fbb1a4..96418e6 100644
--- a/core/Driver/SQL/SQL.class.php
+++ b/core/Driver/SQL/SQL.class.php
@@ -143,7 +143,7 @@ abstract class SQL {
     $returningCol = $insert->getReturning();
     $returning = $this->getReturning($returningCol);
 
-    $query = "INSERT INTO $tableName$columnStr VALUES$values$onDuplicateKey$returning";
+    $query = "INSERT INTO $tableName$columnStr VALUES $values$onDuplicateKey$returning";
     if($insert->dump) { var_dump($query); var_dump($parameters); }
     $res = $this->execute($query, $parameters, !empty($returning));
     $success = ($res !== FALSE);
diff --git a/core/Driver/SQL/Strategy/UpdateStrategy.class.php b/core/Driver/SQL/Strategy/UpdateStrategy.class.php
index 171d3d1..56df47a 100644
--- a/core/Driver/SQL/Strategy/UpdateStrategy.class.php
+++ b/core/Driver/SQL/Strategy/UpdateStrategy.class.php
@@ -5,10 +5,16 @@ namespace Driver\SQL\Strategy;
 class UpdateStrategy extends Strategy {
 
   private array $values;
+  private array $conflictingColumns;
 
-  public function __construct($values) {
+  public function __construct($conflictingColumns, $values) {
+    $this->conflictingColumns = $conflictingColumns;
     $this->values = $values;
   }
 
+  public function getConflictingColumns() {
+    return $this->conflictingColumns;
+  }
+
   public function getValues() { return $this->values; }
 }
\ No newline at end of file
diff --git a/core/Objects/User.class.php b/core/Objects/User.class.php
index 088e745..1fb423b 100644
--- a/core/Objects/User.class.php
+++ b/core/Objects/User.class.php
@@ -239,13 +239,28 @@ class User extends ApiObject {
 
   public function processVisit() {
     if ($this->sql && isset($_COOKIE["PHPSESSID"]) && !empty($_COOKIE["PHPSESSID"])) {
+
+      if ($this->isBot()) {
+        return;
+      }
+
       $cookie = $_COOKIE["PHPSESSID"];
       $month = (new DateTime())->format("Ym");
 
       $this->sql->insert("Visitor", array("cookie", "month"))
         ->addRow($cookie, $month)
-        ->onDuplicateKeyStrategy(new UpdateStrategy(array("count" => new Add("count", 1))))
+        ->onDuplicateKeyStrategy(new UpdateStrategy(
+          array("month", "cookie"),
+          array("count" => new Add("Visitor.count", 1))))
         ->execute();
     }
   }
+
+  private function isBot() {
+    if (!isset($_SERVER["HTTP_USER_AGENT"]) || empty($_SERVER["HTTP_USER_AGENT"])) {
+      return false;
+    }
+
+    return preg_match('/robot|spider|crawler|curl|^$/i', $_SERVER['HTTP_USER_AGENT']) === 1;
+  }
 }