diff --git a/htdocs/core/class/cunits.class.php b/htdocs/core/class/cunits.class.php
index a25250516f4..096ae47a7b8 100644
--- a/htdocs/core/class/cunits.class.php
+++ b/htdocs/core/class/cunits.class.php
@@ -386,4 +386,77 @@ class CUnits // extends CommonObject
 			return 1;
 		}
 	}
+
+
+	/**
+	 * Get unit from code
+	 * @param string $code code of unit
+	 * @param string $mode 0= id , short_label=Use short label as value, code=use code
+	 * @return int            <0 if KO, Id of code if OK
+	 */
+	public function getUnitFromCode($code, $mode = 'code')
+	{
+
+		if($mode == 'short_label'){
+			return dol_getIdFromCode($this->db, $code, 'c_units', 'short_label', 'rowid');
+		}
+		elseif($mode == 'code'){
+			return dol_getIdFromCode($this->db, $code, 'c_units', 'code', 'rowid');
+		}
+
+		return $code;
+	}
+
+	/**
+	 * Unit converter
+	 * @param double $value value to convert
+	 * @param int $fk_unit current unit id of value
+	 * @param int $fk_new_unit the id of unit to convert in
+	 * @return double
+	 */
+	public function unitConverter($value, $fk_unit, $fk_new_unit = 0)
+	{
+		$value  = doubleval(price2num($value));
+		$fk_unit = intval($fk_unit);
+
+		// Calcul en unité de base
+		$scaleUnitPow = $this->scaleOfUnitPow($fk_unit);
+
+		// convert to standard unit
+		$value  = $value * $scaleUnitPow;
+		if($fk_new_unit !=0 ){
+			// Calcul en unité de base
+			$scaleUnitPow = $this->scaleOfUnitPow($fk_new_unit);
+			if(!empty($scaleUnitPow))
+			{
+				// convert to new unit
+				$value  = $value / $scaleUnitPow;
+			}
+		}
+		return round($value, 2);
+	}
+
+
+
+	/**
+	 * get scale of unit factor
+	 * @param $id int id of unit in dictionary
+	 * @return float|int
+	 */
+	public function scaleOfUnitPow($id)
+	{
+		$base = 10;
+		// TODO : add base col into unit dictionary table
+		$unit = $this->db->getRow('SELECT scale, unit_type from '.MAIN_DB_PREFIX.'c_units WHERE rowid = '.intval($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 doubleval($unit->scale);
+			}
+
+			return pow($base, doubleval($unit->scale));
+		}
+
+		return 0;
+	}
 }
diff --git a/htdocs/core/db/DoliDB.class.php b/htdocs/core/db/DoliDB.class.php
index 96e76097877..2818eff65e2 100644
--- a/htdocs/core/db/DoliDB.class.php
+++ b/htdocs/core/db/DoliDB.class.php
@@ -297,4 +297,48 @@ abstract class DoliDB implements Database
 	{
 		return $this->lastqueryerror;
 	}
+
+	/**
+	 * Return first result from query as object
+	 * Note : This method executes a given SQL query and retrieves the first row of results as an object. It should only be used with SELECT queries
+	 * Dont add LIMIT to your query, it will be added by this method
+	 * @param string $sql the sql query string
+	 * @return bool| object
+	 */
+	public function getRow($sql)
+	{
+		$sql .= ' LIMIT 1;';
+
+		$res = $this->query($sql);
+		if ($res)
+		{
+			return $this->fetch_object($res);
+		}
+
+		return false;
+	}
+
+	/**
+	 * return all results from query as an array of objects
+	 * Note : This method executes a given SQL query and retrieves all row of results as an array of objects. It should only be used with SELECT queries
+	 * be carefull with this method use it only with some limit of results to avoid performences loss
+	 * @param string $sql the sql query string
+	 * @return bool| array
+	 */
+	public function getRows($sql)
+	{
+		$res = $this->query($sql);
+		if ($res)
+		{
+			$results = array();
+			if($this->num_rows($res) > 0){
+				while ($obj = $this->fetch_object($res)){
+					$results[] = $obj;
+				}
+			}
+			return $results;
+		}
+
+		return false;
+	}
 }