diff --git a/htdocs/core/class/cunits.class.php b/htdocs/core/class/cunits.class.php
index d7571b8ca90..dfc22fd37ec 100644
--- a/htdocs/core/class/cunits.class.php
+++ b/htdocs/core/class/cunits.class.php
@@ -463,22 +463,30 @@ class CUnits // extends CommonObject
 	}
 
 	/**
-	 * get scale of unit factor
-	 * @param int $id id of unit in dictionary
-	 * @return float|int
+	 * Get scale of unit factor
+	 *
+	 * @param 	int 		$id 	Id of unit in dictionary
+	 * @return 	float|int			Scale of unit
 	 */
 	public function scaleOfUnitPow($id)
 	{
 		$base = 10;
-		// TODO : add base col into unit dictionary table
-		$unit = $this->db->getRow("SELECT scale, unit_type from ".$this->db->prefix()."c_units WHERE rowid = ".intval($id));
-		if ($unit) {
-			// TODO : if base exist in unit dictionary table remove this convertion exception and update convertion infos in database exemple time hour currently scale 3600 will become scale 2 base 60
-			if ($unit->unit_type == 'time') {
-				return floatval($unit->scale);
-			}
 
-			return pow($base, floatval($unit->scale));
+		$sql = "SELECT scale, unit_type FROM ".$this->db->prefix()."c_units WHERE rowid = ".((int) $id);
+
+		$resql = $this->db->query($sql);
+		if ($resql) {
+			// TODO : add base col into unit dictionary table
+			$unit = $this->db->fetch_object($sql);
+			if ($unit) {
+				// TODO : if base exists in unit dictionary table, remove this convertion exception and update convertion infos in database.
+				// Example time hour currently scale 3600 will become scale 2 base 60
+				if ($unit->unit_type == 'time') {
+					return floatval($unit->scale);
+				}
+
+				return pow($base, floatval($unit->scale));
+			}
 		}
 
 		return 0;
diff --git a/htdocs/core/class/validate.class.php b/htdocs/core/class/validate.class.php
index d3aa5707c05..ac4c14f7937 100644
--- a/htdocs/core/class/validate.class.php
+++ b/htdocs/core/class/validate.class.php
@@ -281,14 +281,17 @@ class Validate
 		}
 
 		foreach ($value_arr as $val) {
-			$sql = "SELECT ".$col." FROM ".$this->db->prefix().$table." WHERE ".$col." = '".$this->db->escape($val)."'"; // nore quick than count(*) to check existing of a row
-			$resql = $this->db->getRow($sql);
+			$sql = "SELECT ".$col." FROM ".$this->db->prefix().$table." WHERE ".$col." = '".$this->db->escape($val)."' LIMIT 1"; // more quick than count(*) to check existing of a row
+			$resql = $this->db->query($sql);
 			if ($resql) {
-				continue;
-			} else {
-				$this->error = $this->outputLang->trans('RequireValidExistingElement');
-				return false;
+				$obj = $this->db->fetch_object($resql);
+				if ($obj) {
+					continue;
+				}
 			}
+			// If something was wrong
+			$this->error = $this->outputLang->trans('RequireValidExistingElement');
+			return false;
 		}
 
 		return true;
diff --git a/htdocs/variants/class/ProductCombination.class.php b/htdocs/variants/class/ProductCombination.class.php
index 2de511811a7..63e721c0d37 100644
--- a/htdocs/variants/class/ProductCombination.class.php
+++ b/htdocs/variants/class/ProductCombination.class.php
@@ -1057,12 +1057,16 @@ class ProductCombinationLevel
 	 */
 	public function fetch($rowid)
 	{
-		$sql = "SELECT rowid, fk_product_attribute_combination, fk_price_level, variation_price, variation_price_percentage FROM ".MAIN_DB_PREFIX.$this->table_element." WHERE rowid = ".(int) $rowid;
+		$sql = "SELECT rowid, fk_product_attribute_combination, fk_price_level, variation_price, variation_price_percentage";
+		$sql .= " FROM ".MAIN_DB_PREFIX.$this->table_element;
+		$sql .= " WHERE rowid = ".(int) $rowid;
 
-		$obj = $this->db->getRow($sql);
-
-		if ($obj) {
-			return $this->fetchFormObj($obj);
+		$resql = $this->db->query($sql);
+		if ($resql) {
+			$obj = $this->db->fetch_object($resql);
+			if ($obj) {
+				return $this->fetchFormObj($obj);
+			}
 		}
 
 		return -1;
@@ -1141,11 +1145,14 @@ class ProductCombinationLevel
 			$sql = "SELECT rowid id";
 			$sql .= " FROM ".MAIN_DB_PREFIX.$this->table_element;
 			$sql .= " WHERE fk_product_attribute_combination = ".(int) $this->fk_product_attribute_combination;
-			$sql .= ' AND fk_price_level = '.intval($this->fk_price_level);
+			$sql .= ' AND fk_price_level = '.((int) $this->fk_price_level);
 
-			$existObj = $this->db->getRow($sql);
-			if ($existObj) {
-				$this->id = $existObj->id;
+			$resql = $this->db->query($sql);
+			if ($resql) {
+				$obj = $this->db->fetch_object($resql);
+				if ($obj) {
+					$this->id = $obj->id;
+				}
 			}
 		}