diff --git a/src/Libs/Model.php b/src/Libs/Model.php
index 5fda117..d6d8c8f 100644
--- a/src/Libs/Model.php
+++ b/src/Libs/Model.php
@@ -23,11 +23,6 @@ use ReflectionProperty;
 #[AllowDynamicProperties]
 class Model
 {
-    /**
-     * @var array Attributes that should be set to NULL on update.
-     */
-    protected array $dbSetToNull = [];
-
     /**
      * @var string The name of the primary key column.
      */
@@ -161,7 +156,23 @@ class Model
 
         try {
             $prepared = $db->prepare($query);
-            $prepared->execute(static::$dbQueryVariables);
+            foreach (static::$dbQueryVariables as $key => $value) {
+                // Detectar el tipo de dato para elegir la constante de PDO
+                $type = PDO::PARAM_STR; // Por defecto string
+                if (is_int($value)) {
+                    $type = PDO::PARAM_INT;
+                }
+                if (is_bool($value)) {
+                    $type = PDO::PARAM_BOOL;
+                }
+                if (is_null($value)) {
+                    $type = PDO::PARAM_NULL;
+                }
+
+                $prepared->bindValue($key, $value, $type);
+            }
+
+            $prepared->execute();
         } catch (PDOException $e) {
             if ($db->inTransaction()) {
                 $db->rollBack();
@@ -354,6 +365,11 @@ class Model
         $result     = [];
 
         foreach ($properties as $property) {
+            // Avoid save unset variables
+            if ($property->getType() && !$property->isInitialized($this)) {
+                continue;
+            }
+
             if (!in_array($property->name, static::$dbIgnoreSave)) {
                 $name = $this->camelCaseToSnakeCase($property->name);
                 $result[$name] = $this->castToDbValue($this->{$property->name});
@@ -375,10 +391,6 @@ class Model
      */
     protected function castToDbValue(mixed $value): mixed
     {
-        if (is_bool($value)) {
-            return $value ? '1' : '0';
-        }
-
         if ($value instanceof \UnitEnum) {
             return $value->value ?? $value->name;
         }
@@ -457,25 +469,22 @@ class Model
         $atts = $this->getVars();
         static::$dbQueryVariables = [];
 
+        $set = [];
         foreach ($atts as $key => $value) {
-            if (isset($value)) {
-                if (in_array($key, $this->dbSetToNull)) {
-                    $set[] = "$key=NULL";
-                } else {
-                    $set[] = "$key=:$key";
-                    static::$dbQueryVariables[':' . $key] = $value;
-                }
+            if ($value !== null) {
+                $set[] = "$key=:$key";
+                static::$dbQueryVariables[':' . $key] = $value;
             } else {
-                if (in_array($key, $this->dbSetToNull)) {
-                    $set[] = "$key=NULL";
-                }
+                $set[] = "$key=NULL";
             }
         }
 
         $table = static::table();
         $pk = static::$dbPrimaryKey;
         $pkv = $this->$pk;
-        $sql = "UPDATE $table SET " . join(', ', $set) . " WHERE $pk='$pkv'";
+        $sql = "UPDATE $table SET " . join(', ', $set) . " WHERE $pk=:$pk";
+        static::$dbQueryVariables[":$pk"] = $pkv;
+
         static::query($sql);
     }
 
@@ -1170,22 +1179,4 @@ class Model
 
         return $instances;
     }
-
-    /**
-     * Allows defining an attribute's value as null.
-     * Only works for updating an element in the DB, not for inserting.
-     *
-     * @param array $attributes
-     *                          Attribute or array of attributes that will be set to null.
-     *
-     * @return void
-     */
-    public function setNull(string ...$attributes): void
-    {
-        foreach ($attributes as $att) {
-            if (!in_array($att, $this->dbSetToNull)) {
-                $this->dbSetToNull[] = $att;
-            }
-        }
-    }
 }