N°3171 - Friendly name and obsolescence flag not refreshed (#151)

- Compute any type of expression on server side - Recompute friendly name and obsolescence flag on server side (DBOBject) - Bonus : compute dependency for external keys
2026-02-13 07:24:13 +01:00 · 2020-07-10 17:26:37 +02:00
parent b1fa429234
commit acf0548c4c
9 changed files with 1435 additions and 51 deletions
--- a/core/attributedef.class.inc.php
+++ b/core/attributedef.class.inc.php
@@ -6653,6 +6653,23 @@ class AttributeExternalKey extends AttributeDBFieldVoid
 		return (int)$proposedValue;
 	}

+	public function GetPrerequisiteAttributes($sClass = null)
+	{
+		$aAttributes = parent::GetPrerequisiteAttributes($sClass);
+		$oExpression = DBSearch::FromOQL($this->GetValuesDef()->GetFilterExpression())->GetCriteria();
+		foreach ($oExpression->GetParameters('this') as $sAttCode)
+		{
+			// Skip the id as it cannot change anyway
+			if ($sAttCode =='id') continue;
+
+			if (!in_array($sAttCode, $aAttributes))
+			{
+				$aAttributes[] = $sAttCode;
+			}
+		}
+		return $aAttributes;
+	}
+
 	public function GetMaximumComboLength()
 	{
 		return $this->GetOptional('max_combo_length', MetaModel::GetConfig()->Get('max_combo_length'));
@@ -11561,7 +11578,17 @@ class AttributeFriendlyName extends AttributeDefinition

 	public function GetPrerequisiteAttributes($sClass = null)
 	{
-		return $this->GetOptional("depends_on", array());
+		// Code duplicated with AttributeObsolescenceFlag
+		$aAttributes = $this->GetOptional("depends_on", array());
+		$oExpression = $this->GetOQLExpression();
+		foreach ($oExpression->ListRequiredFields() as $sClass => $sAttCode)
+		{
+			if (!in_array($sAttCode, $aAttributes))
+			{
+				$aAttributes[] = $sAttCode;
+			}
+		}
+		return $aAttributes;
 	}

 	public static function IsScalar()
@@ -12793,7 +12820,17 @@ class AttributeObsolescenceFlag extends AttributeBoolean

 	public function GetPrerequisiteAttributes($sClass = null)
 	{
-		return $this->GetOptional("depends_on", array());
+		// Code duplicated with AttributeFriendlyName
+		$aAttributes = $this->GetOptional("depends_on", array());
+		$oExpression = $this->GetOQLExpression();
+		foreach ($oExpression->ListRequiredFields() as $sClass => $sAttCode)
+		{
+			if (!in_array($sAttCode, $aAttributes))
+			{
+				$aAttributes[] = $sAttCode;
+			}
+		}
+		return $aAttributes;
 	}

 	public function IsDirectField()
--- a/core/dbobject.class.php
+++ b/core/dbobject.class.php
@@ -569,43 +569,41 @@ abstract class DBObject implements iDisplay
 			$this->Reload();
 		}

-		if ($oAttDef->IsExternalKey())
+		if ($oAttDef->IsExternalKey() && is_object($value))
 		{
-			if (is_object($value))
+			// Setting an external key with a whole object (instead of just an ID)
+			// let's initialize also the external fields that depend on it
+			// (useful when building objects in memory and not from a query)
+			/** @var \AttributeExternalKey $oAttDef */
+			if ((get_class($value) != $oAttDef->GetTargetClass()) && (!is_subclass_of($value, $oAttDef->GetTargetClass())))
 			{
-				// Setting an external key with a whole object (instead of just an ID)
-				// let's initialize also the external fields that depend on it
-				// (useful when building objects in memory and not from a query)
-				/** @var \AttributeExternalKey $oAttDef */
-				if ( (get_class($value) != $oAttDef->GetTargetClass()) && (!is_subclass_of($value, $oAttDef->GetTargetClass())))
-				{
-					throw new CoreUnexpectedValue("Trying to set the value of '$sAttCode', to an object of class '".get_class($value)."', whereas it's an ExtKey to '".$oAttDef->GetTargetClass()."'. Ignored");
-				}
+				throw new CoreUnexpectedValue("Trying to set the value of '$sAttCode', to an object of class '".get_class($value)."', whereas it's an ExtKey to '".$oAttDef->GetTargetClass()."'. Ignored");
+			}

-				foreach(MetaModel::ListAttributeDefs(get_class($this)) as $sCode => $oDef)
+			foreach (MetaModel::ListAttributeDefs(get_class($this)) as $sCode => $oDef)
+			{
+				/** @var \AttributeExternalField $oDef */
+				if ($oDef->IsExternalField() && ($oDef->GetKeyAttCode() == $sAttCode))
 				{
-					/** @var \AttributeExternalField $oDef */
-					if ($oDef->IsExternalField() && ($oDef->GetKeyAttCode() == $sAttCode))
-					{
-						/** @var \DBObject $value */
-						$this->m_aCurrValues[$sCode] = $value->Get($oDef->GetExtAttCode());
-						$this->m_aLoadedAtt[$sCode] = true;
-					}
+					/** @var \DBObject $value */
+					$this->m_aCurrValues[$sCode] = $value->Get($oDef->GetExtAttCode());
+					$this->m_aLoadedAtt[$sCode] = true;
+				}
+				elseif (in_array($sAttCode, $oDef->GetPrerequisiteAttributes(get_class($this))))
+				{
+					$this->m_aCurrValues[$sCode] = $this->GetDefaultValue($sCode);
+					unset($this->m_aLoadedAtt[$sCode]);
 				}
 			}
-			else if ($this->m_aCurrValues[$sAttCode] != $value)
+		}
+		else if ($this->m_aCurrValues[$sAttCode] !== $value)
+		{
+			// Invalidate dependent fields so that they get reloaded in case they are needed (See Get())
+			//
+			foreach (MetaModel::GetDependentAttributes(get_class($this), $sAttCode) as $sCode)
 			{
-				// Setting an external key, but no any other information is available...
-				// Invalidate the corresponding fields so that they get reloaded in case they are needed (See Get())
-				foreach(MetaModel::ListAttributeDefs(get_class($this)) as $sCode => $oDef)
-				{
-					/** @var \AttributeExternalKey $oDef */
-					if ($oDef->IsExternalField() && ($oDef->GetKeyAttCode() == $sAttCode))
-					{
-						$this->m_aCurrValues[$sCode] = $this->GetDefaultValue($sCode);
-						unset($this->m_aLoadedAtt[$sCode]);
-					}
-				}
+				$this->m_aCurrValues[$sCode] = $this->GetDefaultValue($sCode);
+				unset($this->m_aLoadedAtt[$sCode]);
 			}
 		}
 		if ($oAttDef->IsLinkSet() && ($value != null))
@@ -787,20 +785,20 @@ abstract class DBObject implements iDisplay
 			{
 				// Standard case... we have the information directly
 			}
-			elseif ($this->m_bIsInDB && !$this->m_bDirty)
+			elseif ($this->m_bIsInDB && !$this->m_bFullyLoaded && !$this->m_bDirty)
 			{
 				// Lazy load (polymorphism): complete by reloading the entire object
-				// #@# non-scalar attributes.... handle that differently?
 				$oKPI = new ExecutionKPI();
 				$this->Reload();
 				$oKPI->ComputeStats('Reload', get_class($this).'/'.$sAttCode);
 			}
-			elseif ($sAttCode == 'friendlyname')
+			elseif ($oAttDef->IsBasedOnOQLExpression())
 			{
-				// The friendly name is not computed and the object is dirty
-				// Todo: implement the computation of the friendly name based on sprintf()
-				// 
-				$this->m_aCurrValues[$sAttCode] = '';
+				// Recompute -which is likely to call Get()
+				//
+				/** @var AttributeFriendlyName|\AttributeObsolescenceFlag $oAttDef */
+				$this->m_aCurrValues[$sAttCode] = $this->EvaluateExpression($oAttDef->GetOQLExpression());
+				$this->m_aLoadedAtt[$sAttCode] = true;
 			}
 			else
 			{
@@ -5358,5 +5356,33 @@ abstract class DBObject implements iDisplay
 				break;
 		}
 	}
+
+	public function EvaluateExpression(Expression $oExpression)
+	{
+		$aFields = $oExpression->ListRequiredFields();
+		$aArgs = array();
+		foreach ($aFields as $sFieldDesc)
+		{
+			$aFieldParts = explode('.', $sFieldDesc);
+			if (count($aFieldParts) == 2)
+			{
+				$sClass = $aFieldParts[0];
+				$sAttCode = $aFieldParts[1];
+			}
+			else
+			{
+				$sClass = get_class($this);
+				$sAttCode = $aFieldParts[0];
+			}
+			if (get_class($this) != $sClass) continue;
+			if (!MetaModel::IsValidAttCode(get_class($this), $sAttCode)) continue;
+
+			$oAttDef = MetaModel::GetAttributeDef(get_class($this), $sAttCode);
+			$aSQLValues = $oAttDef->GetSQLValues($this->m_aCurrValues[$sAttCode]);
+			$value = reset($aSQLValues);
+			$aArgs[$sFieldDesc] = $value;
+		}
+		return $oExpression->Evaluate($aArgs);
+	}
 }

--- a/core/metamodel.class.php
+++ b/core/metamodel.class.php
@@ -944,11 +944,6 @@ abstract class MetaModel
 	{
 		self::_check_subclass($sClass);
 		$oAtt = self::GetAttributeDef($sClass, $sAttCode);
-		// Temporary implementation: later, we might be able to compute
-		// the dependencies, based on the attributes definition
-		// (allowed values and default values)
-
-		// Even non-writable attributes (like ExternalFields) can now have Prerequisites
 		return $oAtt->GetPrerequisiteAttributes();
 	}

--- a/core/oql/expression.class.inc.php
+++ b/core/oql/expression.class.inc.php
@@ -21,6 +21,9 @@ class MissingQueryArgument extends CoreException
 {
 }

+class NotYetEvaluatedExpression extends CoreException
+{
+}

 /**
 * @method Check($oModelReflection, array $aAliases, $sSourceQuery)
@@ -109,6 +112,47 @@ abstract class Expression
 	 */
 	abstract public function RenderExpression($bForSQL = false, &$aArgs = null, $bRetrofitParams = false);

+	/**
+	 * Collect parameters, i.e. :parameter
+	 *
+	 * @param null $sParentFilter
+	 *
+	 * @return array
+	 */
+	public function GetParameters($sParentFilter = null)
+	{
+		$aParameters = array();
+		$unused = $this->RenderExpression(false, $aParameters, true);
+
+		if (!is_null($sParentFilter)) $sParentFilter .= '->';
+
+		$aRet = array();
+		foreach($aParameters as $sParameter => $unused)
+		{
+			if (is_null($sParentFilter))
+			{
+				$aRet[] = $sParameter;
+			}
+			else
+			{
+				if (substr($sParameter, 0, strlen($sParentFilter)) == $sParentFilter)
+				{
+					$aRet[] = substr($sParameter, strlen($sParentFilter));
+				}
+			}
+		}
+		return $aRet;
+	}
+
+	/**
+	 * Evaluate the value of the expression
+	 *
+	 * @param array $aArgs
+	 *
+	 * @throws \Exception if terms cannot be evaluated as scalars
+	 */
+	abstract public function Evaluate(array $aArgs);
+
 	/**
 	 * Recursively renders the expression as a structure (array) suitable for a JSON export
 	 *
@@ -319,6 +363,16 @@ class SQLExpression extends Expression
 		return $this->m_sSQL;
 	}

+	/**
+	 * Evaluate the value of the expression
+	 * @param array $aArgs
+	 * @throws \Exception if terms cannot be evaluated as scalars
+*/
+	public function Evaluate(array $aArgs)
+	{
+		throw new Exception('a nested query cannot be evaluated');
+	}
+
 	// recursive rendering
 	public function toJSON(&$aArgs = null, $bRetrofitParams = false)
 	{
@@ -466,6 +520,149 @@ class BinaryExpression extends Expression
 		return "($sLeft $sOperator $sRight)";
 	}

+	/**
+	 * Evaluate the value of the expression
+	 * @param array $aArgs
+	 * @return mixed
+	 * @throws \Exception if terms cannot be evaluated as scalars
+*/
+	public function Evaluate(array $aArgs)
+	{
+		$mLeft = $this->GetLeftExpr()->Evaluate($aArgs);
+		$mRight = $this->GetRightExpr()->Evaluate($aArgs);
+
+		$sOperator = $this->GetOperator();
+		$sType = null;
+		switch($sOperator)
+		{
+			case '+':
+			case '-':
+			case '*':
+			case '/':
+				$sType = 'maths';
+				break;
+			case '=':
+			case '!=':
+			case '<>':
+				$sType = 'comp';
+				break;
+			case '>':
+			case '>=':
+			case '<':
+			case '<=':
+				$sType = 'numcomp';
+				break;
+			case 'OR':
+			case 'AND':
+				$sType = 'logical';
+				break;
+			case 'LIKE':
+				$sType = 'like';
+				break;
+			default:
+				throw new Exception("Operator '$sOperator' not yet supported");
+		}
+		switch ($sType){
+			case 'logical':
+				$bLeft = static::CastToBool($mLeft);
+				$bRight = static::CastToBool($mRight);
+				switch ($sOperator)
+				{
+					case 'OR':
+						$result = (int)($bLeft || $bRight);
+						break;
+					case 'AND':
+						$result = (int)($bLeft && $bRight);
+						break;
+					default:
+						throw new Exception("Logic: unknown operator '$sOperator'");
+				}
+				break;
+
+			case 'maths':
+				$iLeft = (int) $mLeft;
+				$iRight = (int) $mRight;
+				switch ($sOperator)
+				{
+					case '+' : $result = $iLeft + $iRight; break;
+					case '-' : $result = $iLeft - $iRight; break;
+					case '*' : $result = $iLeft * $iRight; break;
+					case '/' : $result = $iLeft / $iRight; break;
+					default:
+						throw new Exception("Logic: unknown operator '$sOperator'");
+				}
+				break;
+			case 'comp':
+				$left = $mLeft;
+				$right = $mRight;
+				switch ($sOperator)
+				{
+					case '=' : $result = ($left == $right); break;
+					case '!=' : $result = ($left != $right); break;
+					case '<>' : $result = ($left != $right); break;
+					default:
+						throw new Exception("Logic: unknown operator '$sOperator'");
+				}
+				break;
+			case 'numcomp':
+				$iLeft = static::ComparableValue($mLeft);
+				$iRight = static::ComparableValue($mRight);
+				switch ($sOperator)
+				{
+					case '=' : $result = ($iLeft == $iRight); break;
+					case '>' : $result = ($iLeft > $iRight); break;
+					case '<' : $result = ($iLeft < $iRight); break;
+					case '>=' : $result = ($iLeft >= $iRight); break;
+					case '<=' : $result = ($iLeft <= $iRight); break;
+					case '!=' : $result = ($iLeft != $iRight); break;
+					case '<>' : $result = ($iLeft != $iRight); break;
+					default:
+						throw new Exception("Logic: unknown operator '$sOperator'");
+				}
+				break;
+			case 'like':
+				$sEscaped = preg_quote($mRight, '/');
+				$sEscaped = str_replace(array('%', '_', '\\\\.*', '\\\\.'), array('.*', '.', '%', '_'), $sEscaped);
+				$result = (int) preg_match("/$sEscaped/i", $mLeft);
+				break;
+		}
+		return $result;
+	}
+
+	static protected function CastToBool($mValue)
+	{
+		if (is_string($mValue))
+		{
+			if (is_numeric($mValue))
+			{
+				return abs($mValue) > 0;
+			}
+			return false;
+		}
+		return (bool)$mValue;
+	}
+	static protected function ComparableValue($mixed)
+	{
+		if (is_string($mixed))
+		{
+			$oDate = new \DateTime($mixed);
+			if (($oDate->format('Y-m-d') == $mixed) || ($oDate->format('Y-m-d H:i:s') == $mixed))
+			{
+				$iRet = $oDate->format('U');
+			}
+			else
+			{
+				$iRet = (int) $mixed;
+			}
+		}
+		else
+		{
+			$iRet = $mixed;
+		}
+
+		return $iRet;
+	}
+
 	/**
 	 * {@inheritDoc}
 	 * @throws \MissingQueryArgument
@@ -865,6 +1062,16 @@ class MatchExpression extends BinaryExpression
 		return $sRet;
 	}

+	/**
+	 * Evaluate the value of the expression
+	 * @param array $aArgs
+	 * @throws \Exception if terms cannot be evaluated as scalars
+*/
+	public function Evaluate(array $aArgs)
+	{
+		throw new Exception('evaluation of MATCHES not implemented yet');
+	}
+
 	public function Translate($aTranslationData, $bMatchAll = true, $bMarkFieldsAsResolved = true)
 	{
 		/** @var \FieldExpression $oLeft */
@@ -903,6 +1110,16 @@ class UnaryExpression extends Expression
 		return CMDBSource::Quote($this->m_value);
 	}

+	/**
+	 * Evaluate the value of the expression
+	 * @param array $aArgs
+	 * @throws \Exception if terms cannot be evaluated as scalars
+*/
+	public function Evaluate(array $aArgs)
+	{
+		return $this->m_value;
+	}
+
 	/**
 	 * {@inheritDoc}
 	 * @throws \MissingQueryArgument
@@ -1049,6 +1266,16 @@ class ScalarExpression extends UnaryExpression
 		return $sRet;
 	}

+	/**
+	 * Evaluate the value of the expression
+	 * @param array $aArgs
+	 * @throws \Exception if terms cannot be evaluated as scalars
+*/
+	public function Evaluate(array $aArgs)
+	{
+		return $this->m_value;
+	}
+
 	/**
 	 * {@inheritDoc}
 	 * @see Expression::ToJSON()
@@ -1357,6 +1584,21 @@ class FieldExpression extends UnaryExpression
 		return "`{$this->m_sParent}`.`{$this->m_sName}`";
 	}

+	/**
+	 * Evaluate the value of the expression
+	 * @param array $aArgs
+	 * @throws \Exception if terms cannot be evaluated as scalars
+*/
+	public function Evaluate(array $aArgs)
+	{
+		$sKey = empty($this->m_sParent) ? $this->m_sName : "{$this->m_sParent}.{$this->m_sName}";
+		if (!array_key_exists($sKey, $aArgs))
+		{
+			throw new Exception("Missing field '$sKey' from context");
+		}
+		return $aArgs[$sKey];
+	}
+
 	/**
 	 * {@inheritDoc}
 	 * @see Expression::ToJSON()
@@ -1412,7 +1654,8 @@ class FieldExpression extends UnaryExpression

 	public function ListRequiredFields()
 	{
-		return array($this->m_sParent.'.'.$this->m_sName);
+		$sField = empty($this->m_sParent) ? $this->m_sName : "{$this->m_sParent}.{$this->m_sName}";
+		return array($sField);
 	}

 	public function CollectUsedParents(&$aTable)
@@ -1793,6 +2036,16 @@ class VariableExpression extends UnaryExpression
 		}
 	}

+	/**
+	 * Evaluate the value of the expression
+	 * @param array $aArgs
+	 * @throws \Exception if terms cannot be evaluated as scalars
+*/
+	public function Evaluate(array $aArgs)
+	{
+		throw new Exception('not implemented yet');
+	}
+
 	/**
 	 * {@inheritDoc}
 	 * @see Expression::ToJSON()
@@ -1933,6 +2186,16 @@ class ListExpression extends Expression
 		return '('.implode(', ', $aRes).')';
 	}

+	/**
+	 * Evaluate the value of the expression
+	 * @param array $aArgs
+	 * @throws \Exception if terms cannot be evaluated as scalars
+*/
+	public function Evaluate(array $aArgs)
+	{
+		throw new Exception('list expression not yet supported');
+	}
+
 	/**
 	 * {@inheritDoc}
 	 * @see Expression::ToJSON()
@@ -2140,6 +2403,16 @@ class NestedQueryExpression extends Expression
 		}
 	}

+	/**
+	 * Evaluate the value of the expression
+	 * @param array $aArgs
+	 * @throws \Exception if terms cannot be evaluated as scalars
+*/
+	public function Evaluate(array $aArgs)
+	{
+		throw new Exception('a nested query cannot be evaluated');
+	}
+
 	public function Browse(Closure $callback)
 	{
 		$callback($this);
@@ -2240,6 +2513,252 @@ class FunctionExpression extends Expression
 		return $this->m_sVerb.'('.implode(', ', $aRes).')';
 	}

+	/**
+	 * Evaluate the value of the expression
+	 * @param array $aArgs
+	 * @throws \Exception if terms cannot be evaluated as scalars
+*/
+	public function Evaluate(array $aArgs)
+	{
+		switch($this->m_sVerb)
+		{
+			case 'CONCAT':
+				$sRet = '';
+				foreach ($this->m_aArgs as $iPos => $oExpr)
+				{
+					$item = $oExpr->Evaluate($aArgs);
+					if (is_null($item)) return null;
+					$sRet .= $item;
+				}
+				return $sRet;
+
+			case 'CONCAT_WS':
+				if (count($this->m_aArgs) < 3)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires at least 3 arguments");
+				}
+				$sSeparator = $this->m_aArgs[0]->Evaluate($aArgs);
+				foreach ($this->m_aArgs as $iPos => $oExpr)
+				{
+					if ($iPos == 0) continue;
+					$item = $oExpr->Evaluate($aArgs);
+					if (is_null($item)) return null;
+					$aStrings[] = $item;
+				}
+				$sRet = implode($sSeparator, $aStrings);
+				return $sRet;
+
+			case 'SUBSTR':
+				if (count($this->m_aArgs) < 2)
+				{
+					 throw new \Exception("Function {$this->m_sVerb} requires at least 2 arguments");
+				}
+				$sString = $this->m_aArgs[0]->Evaluate($aArgs);
+				$iRawPos = $this->m_aArgs[1]->Evaluate($aArgs);
+				$iPos = $iRawPos > 0 ?
+					$iRawPos - 1// 0-based in PHP (1-based in SQL)
+					: $iRawPos; // Negative
+				if (count($this->m_aArgs) == 2)
+				{
+					// Up to the end of the string
+					$sRet = substr($sString, $iPos);
+				}
+				else
+				{
+					// Length specified
+					$iLen = $this->m_aArgs[2]->Evaluate($aArgs);
+					$sRet = substr($sString, $iPos, $iLen);
+				}
+				return $sRet;
+
+			case 'TRIM':
+				if (count($this->m_aArgs) != 1)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires 1 argument");
+				}
+				$sRet = trim($this->m_aArgs[0]->Evaluate($aArgs));
+				return $sRet;
+
+			case 'INET_ATON':
+				if (count($this->m_aArgs) != 1)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires 1 argument");
+				}
+				$sRet = ip2long($this->m_aArgs[0]->Evaluate($aArgs));
+				return $sRet;
+
+			case 'INET_NTOA':
+				if (count($this->m_aArgs) != 1)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires 1 argument");
+				}
+				$sRet = long2ip($this->m_aArgs[0]->Evaluate($aArgs));
+				return $sRet;
+
+			case 'ISNULL':
+				if (count($this->m_aArgs) != 1)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires 1 argument");
+				}
+				$sRet = is_null($this->m_aArgs[0]->Evaluate($aArgs));
+				return $sRet;
+
+			case 'COALESCE':
+				if (count($this->m_aArgs) < 1)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires at least 1 argument");
+				}
+				$ret = null;
+				foreach($this->m_aArgs as $iPos => $oExpr)
+				{
+					$ret = $oExpr->Evaluate($aArgs);
+					if (!is_null($ret)) break;
+				}
+				return $ret;
+
+			case 'IF':
+				if (count($this->m_aArgs) != 3)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires 3 arguments");
+				}
+				$bCond = $this->m_aArgs[0]->Evaluate($aArgs);
+				if ($bCond)
+				{
+					$ret = $this->m_aArgs[1]->Evaluate($aArgs);
+				}
+				else
+				{
+					$ret = $this->m_aArgs[2]->Evaluate($aArgs);
+				}
+				return $ret;
+
+			case 'ELT':
+				if (count($this->m_aArgs) < 2)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires at least 2 arguments");
+				}
+				// First argument is the 1-based position
+				$iPosition = (int) $this->m_aArgs[0]->Evaluate($aArgs);
+				if (($iPosition == 0) || ($iPosition >= count($this->m_aArgs)))
+				{
+					// Out of range
+					$ret = null;
+				}
+				else
+				{
+					$ret = $this->m_aArgs[$iPosition]->Evaluate($aArgs);
+				}
+				return $ret;
+
+			case 'DATE':
+				if (count($this->m_aArgs) != 1)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires 1 argument");
+				}
+				$sRet = date('Y-m-d', strtotime($this->m_aArgs[0]->Evaluate($aArgs)));
+				return $sRet;
+
+			case 'YEAR':
+				if (count($this->m_aArgs) != 1)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires 1 argument");
+				}
+				$iRet = (int) date('Y', strtotime($this->m_aArgs[0]->Evaluate($aArgs)));
+				return $iRet;
+
+			case 'MONTH':
+				if (count($this->m_aArgs) != 1)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires 1 argument");
+				}
+				$iRet = (int) date('m', strtotime($this->m_aArgs[0]->Evaluate($aArgs)));
+				return $iRet;
+
+			case 'DAY':
+				if (count($this->m_aArgs) != 1)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires 1 argument");
+				}
+				$iRet = (int) date('d', strtotime($this->m_aArgs[0]->Evaluate($aArgs)));
+				return $iRet;
+
+			case 'DATE_FORMAT':
+				if (count($this->m_aArgs) != 2)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires 2 arguments");
+				}
+				$oDate = new DateTime($this->m_aArgs[0]->Evaluate($aArgs));
+				$sFormat = $this->m_aArgs[1]->Evaluate($aArgs);
+				$sFormat = str_replace(
+					array('%y', '%x', '%w', '%W', '%v', '%T', '%S', '%r', '%p', '%M', '%l', '%k', '%I', '%h', '%b', '%a', '%D', '%c', '%e', '%Y', '%d', '%m', '%H', '%i', '%s'),
+					array('y', 'o', 'w', 'l', 'W', 'H:i:s', 's', 'h:i:s A', 'A', 'F', 'g', 'H', 'h', 'h','M', 'D', 'jS', 'n', 'j', 'Y', 'd', 'm', 'H', 'i', 's'),
+					$sFormat);
+				if (preg_match('/%j/', $sFormat))
+				{
+					$sFormat = str_replace('%j', date_format($oDate, 'z') + 1, $sFormat);
+				}
+				if (preg_match('/%[fUuVX]/', $sFormat))
+				{
+					throw new NotYetEvaluatedExpression("Expression ".$this->RenderExpression().' cannot be evaluated (known limitation)');
+				}
+				$sRet = date_format($oDate, $sFormat);
+				return $sRet;
+
+			case 'TO_DAYS':
+				if (count($this->m_aArgs) != 1)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires 1 argument");
+				}
+				$oDate = new DateTime($this->m_aArgs[0]->Evaluate($aArgs));
+				$oZero = new DateTime('1582-01-01');
+				$iRet = (int) $oDate->diff($oZero)->format('%a') + 577815;
+				return $iRet;
+
+			case 'FROM_DAYS':
+				if (count($this->m_aArgs) != 1)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires 1 argument");
+				}
+				$iSince1582 = $this->m_aArgs[0]->Evaluate($aArgs) - 577814;
+				$oDate = new DateTime("1582-01-01 +$iSince1582 days");
+				$sRet = $oDate->format('Y-m-d');
+				return $sRet;
+
+			case 'NOW':
+				$sRet = date('Y-m-d H:i:s');
+				return $sRet;
+
+			case 'CURRENT_DATE':
+				$sRet = date('Y-m-d');
+				return $sRet;
+
+			case 'DATE_ADD':
+				if (count($this->m_aArgs) != 2)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires 2 arguments");
+				}
+				$sStartDate = $this->m_aArgs[0]->Evaluate($aArgs);
+				$sInterval = $this->m_aArgs[1]->Evaluate($aArgs);
+				$oDate = new DateTime("$sStartDate +$sInterval");
+				$sRet = $oDate->format('Y-m-d H:i:s');
+				return $sRet;
+
+			case 'DATE_SUB':
+				if (count($this->m_aArgs) != 2)
+				{
+					throw new \Exception("Function {$this->m_sVerb} requires 2 arguments");
+				}
+				$sStartDate = $this->m_aArgs[0]->Evaluate($aArgs);
+				$sInterval = $this->m_aArgs[1]->Evaluate($aArgs);
+				$oDate = new DateTime("$sStartDate -$sInterval");
+				$sRet = $oDate->format('Y-m-d H:i:s');
+				return $sRet;
+
+			default:
+				throw new Exception("Function {$this->m_sVerb} cannot be evaluated -unhandled yet");
+		}
+	}
+
 	/**
 	 * {@inheritDoc}
 	 * @see Expression::ToJSON()
@@ -2566,6 +3085,17 @@ class IntervalExpression extends Expression
 		return 'INTERVAL '.$this->m_oValue->RenderExpression($bForSQL, $aArgs, $bRetrofitParams).' '.$this->m_sUnit;
 	}

+	/**
+	 * Evaluate the value of the expression
+	 * @param array $aArgs
+	 * @throws \Exception if terms cannot be evaluated as scalars
+*/
+	public function Evaluate(array $aArgs)
+	{
+		$iValue = $this->m_oValue->Evaluate($aArgs);
+		return "$iValue {$this->m_sUnit}";
+	}
+
 	/**
 	 * {@inheritDoc}
 	 * @see Expression::ToJSON()
@@ -2684,6 +3214,21 @@ class CharConcatExpression extends Expression
 		return "CAST(CONCAT(".implode(', ', $aRes).") AS CHAR)";
 	}

+	/**
+	 * Evaluate the value of the expression
+	 * @param array $aArgs
+	 * @throws \Exception if terms cannot be evaluated as scalars
+*/
+	public function Evaluate(array $aArgs)
+	{
+		$sRet = '';
+		foreach ($this->m_aExpressions as $oExpr)
+		{
+			$sRet .= $oExpr->Evaluate($aArgs);
+		}
+		return $sRet;
+	}
+
 	/**
 	 * {@inheritDoc}
 	 * @see Expression::ToJSON()
@@ -2825,6 +3370,21 @@ class CharConcatWSExpression extends CharConcatExpression
 		return "CAST(CONCAT_WS($sSep, ".implode(', ', $aRes).") AS CHAR)";
 	}

+	/**
+	 * Evaluate the value of the expression
+	 * @param array $aArgs
+	 * @throws \Exception if terms cannot be evaluated as scalars
+*/
+	public function Evaluate(array $aArgs)
+	{
+		$aRes = array();
+		foreach ($this->m_aExpressions as $oExpr)
+		{
+			$aRes .= $oExpr->Evaluate($aArgs);
+		}
+		return implode($this->m_separator, $aRes);
+	}
+
 	public function Browse(Closure $callback)
 	{
 		$callback($this);
--- a/datamodels/2.x/itop-config-mgmt/datamodel.itop-config-mgmt.xml
+++ b/datamodels/2.x/itop-config-mgmt/datamodel.itop-config-mgmt.xml
@@ -610,9 +610,6 @@
        </field>
        <field id="manager_id" xsi:type="AttributeExternalKey">
          <filter><![CDATA[SELECT Person]]></filter>
-          <dependencies>
-            <attribute id="org_id"/>
-          </dependencies>
          <sql>manager_id</sql>
          <target_class>Person</target_class>
          <is_null_allowed>true</is_null_allowed>
--- a/test/ItopDataTestCase.php
+++ b/test/ItopDataTestCase.php
@@ -713,7 +713,7 @@ class ItopDataTestCase extends ItopTestCase
 			$iId = $oLnk->Get('functionalci_id');
 			if (!empty($aWaitedCIList))
 			{
-				$this->assertTrue(array_key_exists($iId, $aWaitedCIList));
+				$this->assertArrayHasKey($iId, $aWaitedCIList);
 				$this->assertEquals($aWaitedCIList[$iId], $oLnk->Get('impact_code'));
 			}
 		}
@@ -737,7 +737,7 @@ class ItopDataTestCase extends ItopTestCase
 			$iId = $oLnk->Get('contact_id');
 			if (!empty($aWaitedContactList))
 			{
-				$this->assertTrue(array_key_exists($iId, $aWaitedContactList));
+				$this->assertArrayHasKey($iId, $aWaitedContactList);
 				foreach ($aWaitedContactList[$iId] as $sAttCode => $oValue)
 				{
 					if (MetaModel::IsValidAttCode(get_class($oTicket), $sAttCode))
@@ -756,5 +756,29 @@ class ItopDataTestCase extends ItopTestCase
 		$this->iTestOrgId = $oOrg->GetKey();
 	}

-
+	/**
+	 *  Assert that a series of operations will trigger a given number of MySL queries
+	 *
+	 * @param $iExpectedCount  Number of MySQL queries that should be executed
+	 * @param callable $oFunction Operations to perform
+	 *
+	 * @throws \MySQLException
+	 * @throws \MySQLQueryHasNoResultException
+	 */
+	protected static function assertDBQueryCount($iExpectedCount, callable $oFunction)
+	{
+		$iInitialCount = (int) CMDBSource::QueryToScalar("SHOW SESSION STATUS LIKE 'Queries'", 1);
+		$oFunction();
+		$iFinalCount = (int) CMDBSource::QueryToScalar("SHOW SESSION STATUS LIKE 'Queries'", 1);
+		$iCount = $iFinalCount - 1 - $iInitialCount;
+		if ($iCount != $iExpectedCount)
+		{
+			static::fail("Expected $iExpectedCount queries. $iCount have been executed.");
+		}
+		else
+		{
+			// Otherwise PHP Unit will consider that no assertion has been made
+			static::assertTrue(true);
+		}
+	}
 }
--- a/test/core/DBObjectTest.php
+++ b/test/core/DBObjectTest.php
@@ -48,6 +48,7 @@ class DBObjectTest extends ItopDataTestCase

 	/**
 	 * Test default page name
+	 * @covers DBObject::GetUIPage
 	 */
 	public function testGetUIPage()
 	{
@@ -81,6 +82,9 @@ class DBObjectTest extends ItopDataTestCase
 			array('PHP_INT_MIN', false));
 	}

+	/**
+	 * @covers DBObject::GetOriginal
+	 */
 	public function testGetOriginal()
 	{
 		$oObject = $this->CreateUserRequest(190664);
@@ -88,4 +92,114 @@ class DBObjectTest extends ItopDataTestCase
 		static::assertNull($oObject->GetOriginal('sla_tto_passed'));
 	}

+	/**
+	 * @covers DBObject::NewObject
+	 * @covers DBObject::Get
+	 * @covers DBObject::Set
+	 */
+	public function testAttributeRefresh_FriendlyName()
+	{
+		$oObject = \MetaModel::NewObject('Person', array('name' => 'Foo', 'first_name' => 'John', 'org_id' => 3, 'location_id' => 2));
+
+		static::assertEquals('John Foo', $oObject->Get('friendlyname'));
+		$oObject->Set('name', 'Who');
+		static::assertEquals('John Who', $oObject->Get('friendlyname'));
+	}
+
+	/**
+	 * @covers MetaModel::GetObject
+	 * @covers DBObject::Get
+	 * @covers DBObject::Set
+	 */
+	public function testAttributeRefresh_FriendlyNameFromDB()
+	{
+		$oObject = \MetaModel::NewObject('Person', array('name' => 'Gary', 'first_name' => 'Romain', 'org_id' => 3, 'location_id' => 2));
+		$oObject->DBInsert();
+		$iObjKey = $oObject->GetKey();
+
+		$oObject = \MetaModel::GetObject('Person', $iObjKey);
+
+		static::assertEquals('Romain Gary', $oObject->Get('friendlyname'));
+		$oObject->Set('name', 'Duris');
+		static::assertEquals('Romain Duris', $oObject->Get('friendlyname'));
+	}
+
+	/**
+	 * @covers DBObject::NewObject
+	 * @covers DBObject::Get
+	 * @covers DBObject::Set
+	 */
+	public function testAttributeRefresh_ObsolescenceFlag()
+	{
+		$oObject = \MetaModel::NewObject('Person', array('name' => 'Foo', 'first_name' => 'John', 'org_id' => 3, 'location_id' => 2));
+
+		static::assertEquals(false, (bool)$oObject->Get('obsolescence_flag'));
+		$oObject->Set('status', 'inactive');
+		static::assertEquals(true, (bool)$oObject->Get('obsolescence_flag'));
+	}
+
+	/**
+	 * @covers DBObject::NewObject
+	 * @covers DBObject::Get
+	 * @covers DBObject::Set
+	 */
+	public function testAttributeRefresh_ExternalKeysAndFields()
+	{
+		static::assertDBQueryCount(0, function() use (&$oObject){
+			$oObject = \MetaModel::NewObject('Person', array('name' => 'Foo', 'first_name' => 'John', 'org_id' => 3, 'location_id' => 2));
+		});
+		static::assertDBQueryCount(2, function() use (&$oObject){
+			static::assertEquals('Demo', $oObject->Get('org_id_friendlyname'));
+			static::assertEquals('Grenoble', $oObject->Get('location_id_friendlyname'));
+		});
+
+		// External key given as an id
+		static::assertDBQueryCount(1, function() use (&$oObject){
+			$oObject->Set('org_id', 2);
+			static::assertEquals('IT Department', $oObject->Get('org_id_friendlyname'));
+		});
+
+		// External key given as an object
+		static::assertDBQueryCount(1, function() use (&$oBordeaux){
+			$oBordeaux = \MetaModel::GetObject('Location', 1);
+		});
+
+		static::assertDBQueryCount(0, function() use (&$oBordeaux, &$oObject){
+			$oObject->Set('location_id', $oBordeaux);
+			static::assertEquals('IT Department', $oObject->Get('org_id_friendlyname'));
+			static::assertEquals('IT Department', $oObject->Get('org_name'));
+			static::assertEquals('Bordeaux', $oObject->Get('location_id_friendlyname'));
+		});
+	}
+
+	public function testSetExtKeyUnsetDependentAttribute()
+	{
+		$oObject = \MetaModel::NewObject('Person', array('name' => 'Foo', 'first_name' => 'John', 'org_id' => 3, 'location_id' => 2));
+		$oOrg = \MetaModel::GetObject('Organization', 2);
+		$oObject->Set('org_id', $oOrg);
+		static::assertEquals(0, $oObject->Get('location_id'));
+	}
+
+	/**
+	 * @group Integration
+	 */
+	public function testModelExpressions()
+	{
+		foreach (\MetaModel::GetClasses() as $sClass)
+		{
+			if (\MetaModel::IsAbstract($sClass)) continue;
+
+			$oObject = \MetaModel::NewObject($sClass);
+			foreach (\MetaModel::ListAttributeDefs($sClass) as $sAttCode => $oAttDef)
+			{
+				if ($oAttDef->IsBasedOnOQLExpression())
+				{
+					$this->debug("$sClass::$sAttCode");
+					static::assertDBQueryCount(0, function() use (&$oObject, &$oAttDef){
+						$oObject->EvaluateExpression($oAttDef->GetOQLExpression());
+					});
+				}
+			}
+		}
+	}
 }
--- a/test/core/ExpressionEvaluateTest.php
+++ b/test/core/ExpressionEvaluateTest.php
@@ -0,0 +1,535 @@
+<?php
+
+
+namespace Combodo\iTop\Test\UnitTest\Core;
+
+
+use CMDBSource;
+use Combodo\iTop\Test\UnitTest\iTopDataTestCase;
+use DateInterval;
+use DateTime;
+use Expression;
+use FunctionExpression;
+use MetaModel;
+use ScalarExpression;
+
+class ExpressionEvaluateTest extends iTopDataTestCase
+{
+	const USE_TRANSACTION = false;
+
+	/**
+	 * @covers       Expression::GetParameters()
+	 * @dataProvider GetParametersProvider
+	 *
+	 * @param $sExpression
+	 * @param $sParentFilter
+	 * @param $aExpectedParameters
+	 *
+	 * @throws \OQLException
+	 */
+	public function testGetParameters($sExpression, $sParentFilter, $aExpectedParameters)
+	{
+		$oExpression = Expression::FromOQL($sExpression);
+		$aParameters = $oExpression->GetParameters($sParentFilter);
+		sort($aExpectedParameters);
+		sort($aParameters);
+		static::assertEquals($aExpectedParameters, $aParameters);
+	}
+
+	public function GetParametersProvider()
+	{
+		return array(
+			array('1 AND 0 OR :hello + :world', null, array('hello', 'world')),
+			array('1 AND 0 OR :hello + :world', 'this', array()),
+			array(':this->left + :this->right', null, array('this->left', 'this->right')),
+			array(':this->left + :this->right', 'this', array('left', 'right')),
+			array(':this->left + :this->right', 'that', array()),
+			array(':this_left + :this_right', 'this', array()),
+		);
+	}
+
+	/**
+	 * 100x quicker to execute than testExpressionEvaluate
+	 *
+	 * @covers       Expression::Evaluate()
+	 * @covers       Expression::FromOQL()
+	 * @relies-on-dataProvider VariousExpressions
+	 * @throws \OQLException
+	 */
+	public function _testExpressionEvaluateAllAtOnce()
+	{
+		$aTestCases = $this->VariousExpressionsProvider();
+		foreach ($aTestCases as $sCaseId => $aTestArgs)
+		{
+			$this->debug("Case $sCaseId:");
+			$this->testVariousExpressions($aTestArgs[0], $aTestArgs[1]);
+		}
+	}
+
+	/**
+	 * @covers       Expression::Evaluate()
+	 * @covers       Expression::FromOQL()
+	 * @dataProvider VariousExpressionsProvider
+	 *
+	 * @param string $sExpression
+	 * @param string $expectedValue
+	 *
+	 * @throws \OQLException
+	 * @throws \Exception
+	 */
+	public function testVariousExpressions($sExpression, $expectedValue)
+	{
+		$oExpression = Expression::FromOQL($sExpression);
+		$value = $oExpression->Evaluate(array());
+		static::assertEquals($expectedValue, $value);
+	}
+
+	public function VariousExpressionsProvider()
+	{
+		if (false)
+		{
+			$aExpressions = array(
+				// Test case to isolate for troubleshooting purposes
+				array('1+1', 2),
+			);
+		}
+		else
+		{
+			$aExpressions = array(
+				// The bare minimum
+				array('"blah"', 'blah'),
+				array('"\\\\"', '\\'),
+				// Arithmetics
+				array('2+2', 4),
+				array('2+2-2', 2),
+				array('2*(3+4)', 14),
+				array('(2*3)+4', 10),
+				array('2*3+4', 10),
+				// Strings
+				array("CONCAT('hello', 'world')", 'helloworld'),
+				// Not yet parsed - array("CONCAT_WS(' ', 'hello', 'world')", 'hello world'),
+				array("SUBSTR('abcdef', 2, 3)", 'bcd'),
+				array("TRIM(' Sin dolor  ')", 'Sin dolor'),
+				// Comparison operators
+				array('1 = 1', 1),
+				array('1 != 1', 0),
+				array('0 = 1', 0),
+				array('0 != 1', 1),
+				array('2 > 1', 1),
+				array('2 < 1', 0),
+				array('1 > 2', 0),
+				array('2 > 1', 1),
+				array('2 >= 1', 1),
+				array('2 >= 2', 1),
+				array("'the quick brown dog' LIKE '%QUICK%'", 1),
+				array("'the quick brown dog' LIKE '%SLOW%'", 0),
+				array("'the quick brown dog' LIKE '%QU_CK%'", 1),
+				array("'the quick brown dog' LIKE '%QU_ICK%'", 0),
+				array('"400 (km/h)" LIKE "400%"', 1),
+				array('"400 (km/h)" LIKE "100%"', 0),
+				array('"2020-06-12" > "2020-06-11"', 1),
+				array('"2020-06-12" < "2020-06-11"', 0),
+				array('" 2020-06-12" > "2020-06-11"', 0), // Leading spaces => a string
+				array('" 2020-06-12 " > "2020-06-11"', 0), // Trailing spaces => a string
+				array('"2020-06-12 17:35:13" > "2020-06-12 17:35:12"', 1),
+				array('"2020-06-12 17:35:13" < "2020-06-12 17:35:12"', 0),
+				array('"2020-06-12 17:35:13" > "2020-06-12"', 1),
+				array('"2020-06-12 17:35:13" < "2020-06-12"', 0),
+				array('"2020-06-12 00:00:00" = "2020-06-12"', 0),
+				// Logical operators
+				array('0 AND 0', 0),
+				array('1 AND 0', 0),
+				array('0 AND 1', 0),
+				array('1 AND 1', 1),
+				array('0 OR 0', 0),
+				array('0 OR 1', 1),
+				array('1 OR 0', 1),
+				array('1 OR 1', 1),
+				array('1 AND 0 OR 1', 1),
+				// Casting
+				array('1 AND "blah"', 0),
+				array('1 AND "1"', 1),
+				array('1 AND "2"', 1),
+				array('1 AND "0"', 0),
+				array('1 AND "-1"', 1),
+				// Null
+				array('NULL', null),
+				array('1 AND NULL', null),
+				array('CONCAT("Great but...", NULL)', null),
+				array('COALESCE(NULL, 123)', 123),
+				array('COALESCE(321, 123)', 321),
+				array('ISNULL(NULL)', 1),
+				array('ISNULL(123)', 0),
+				// Date functions
+				array("DATE('2020-03-12 13:18:30')", '2020-03-12'),
+				array("DATE_FORMAT('2009-10-04 22:23:00', '%Y %m %d %H %i %s')", '2009 10 04 22 23 00'),
+				array("DATE(NOW()) = CURRENT_DATE()", 1), // Could fail if executed around midnight!
+				array("TO_DAYS('2020-01-02')", 737791),
+				array("FROM_DAYS(737791)", '2020-01-02'),
+				array("YEAR('2020-05-03')", 2020),
+				array("MONTH('2020-05-03')", 5),
+				array("DAY('2020-05-03')", 3),
+				array("DATE_ADD('2020-02-28 18:00:00', INTERVAL 1 HOUR)", '2020-02-28 19:00:00'),
+				array("DATE_ADD('2020-02-28 18:00:00', INTERVAL 1 DAY)", '2020-02-29 18:00:00'),
+				array("DATE_SUB('2020-03-01 18:00:00', INTERVAL 1 HOUR)", '2020-03-01 17:00:00'),
+				array("DATE_SUB('2020-03-01 18:00:00', INTERVAL 1 DAY)", '2020-02-29 18:00:00'),
+				// Misc. functions
+				array('IF(1, 123, 567)', 123),
+				array('IF(0, 123, 567)', 567),
+				array('ELT(3, "a", "b", "c")', 'c'),
+				array('ELT(0, "a", "b", "c")', null),
+				array('ELT(4, "a", "b", "c")', null),
+				array('INET_ATON("128.0.0.1")', 2147483649),
+				array('INET_NTOA(2147483649)', '128.0.0.1'),
+			);
+		}
+
+		// Build a comprehensive index
+		$aRet = array();
+		foreach ($aExpressions as $aExp)
+		{
+			$aRet[$aExp[0]] = $aExp;
+		}
+		return $aRet;
+	}
+
+	/**
+	 * @covers       Expression::Evaluate()
+	 * @dataProvider NotYetParsableExpressionsProvider
+	 *
+	 * @param string $sExpression
+	 * @param string $expectedValue
+	 */
+	public function testNotYetParsableExpressions($sExpression, $expectedValue)
+	{
+		$sNewExpression = "return $sExpression;";
+		$oExpression = eval($sNewExpression);
+		$res = $oExpression->Evaluate(array());
+		static::assertEquals($expectedValue, $res);
+	}
+
+	public function NotYetParsableExpressionsProvider()
+	{
+		$aExpressions = array(
+			array("new \\FunctionExpression('CONCAT_WS', array(new \\ScalarExpression(' '), new \\ScalarExpression('Hello'), new \ScalarExpression('world!')))", 'Hello world!'),
+			array("new \\ScalarExpression('windows\\system32')", 'windows\\system32'),
+			array("new \\BinaryExpression(new \\ScalarExpression('100%'), 'LIKE', new \\ScalarExpression('___\%'))", 1),
+			array("new \\BinaryExpression(new \ScalarExpression('1000'), 'LIKE', new \ScalarExpression('___\%'))", 0),
+			// Net yet parsed - array("TIME(NOW()) = CURRENT_TIME()", 1), // Not relevant
+			// Not yet parsed - array("DATE_ADD('2020-02-28 18:00:00', INTERVAL 1 WEEK)", '2020-03-06 18:00:00'),
+			// Not yet parsed - array("DATE_SUB('2020-03-01 18:00:00', INTERVAL 1 WEEK)", '2020-02-23 18:00:00'),
+			// Not yet parsed - array('ROUND(1.2345, 2)', 1.23),
+			// Not yet parsed - array('FLOOR(1.2)', 1),
+		);
+		// Build a comprehensive index
+		$aRet = array();
+		foreach ($aExpressions as $aExp)
+		{
+			$aRet[$aExp[0]] = $aExp;
+		}
+		return $aRet;
+	}
+
+	/**
+	 * Check that the test data would give the same result when evaluated by MySQL
+	 * It uses the data provider ExpressionProvider, and checks every test case in one single query
+	 *
+	 * @throws \MySQLException
+	 */
+	public function testMySQLEvaluateAllAtOnce()
+	{
+		// Expressions given as an OQL
+		$aTests = array_values($this->VariousExpressionsProvider());
+
+		// Expressions given as a PHP statement
+		foreach (array_values($this->NotYetParsableExpressionsProvider()) as $i => $aTest)
+		{
+			$sNewExpression = "return {$aTest[0]};";
+			$oExpression = eval($sNewExpression);
+			$sExpression = $oExpression->RenderExpression(true);
+			$aTests[] = array($sExpression, $aTest[1]);
+		}
+
+		$aExpressions = array();
+		foreach ($aTests as $i => $aTest)
+		{
+			$aExpressions[] = "{$aTest[0]} as test_$i";
+		}
+
+		$sSelects = implode(', ', $aExpressions);
+		$sQuery = "SELECT $sSelects";
+
+		$this->debug($sQuery);
+		$aResults = CMDBSource::QueryToArray($sQuery);
+
+		foreach ($aTests as $i => $aTest)
+		{
+			$value = $aResults[0]["test_$i"];
+			$expectedValue = $aTest[1];
+			$this->debug("Test #$i: {$aTests[$i][0]} => ".var_export($value, true));
+			static::assertEquals($expectedValue, $value);
+		}
+	}
+
+	/**
+	 * @covers DBObject::EvaluateExpression
+	 * @dataProvider ExpressionsWithObjectFieldsProvider
+	 *
+	 * @param $sClass
+	 * @param $aValues
+	 * @param $sExpression
+	 * @param $expected
+	 *
+	 * @throws \CoreException
+	 * @throws \OQLException
+	 */
+	public function testExpressionsWithObjectFields($sClass, $aValues, $sExpression, $expected)
+	{
+		$oObject = MetaModel::NewObject($sClass, $aValues);
+		$oExpression = Expression::FromOQL($sExpression);
+
+		$res = $oObject->EvaluateExpression($oExpression);
+
+		static::assertEquals($expected, $res);
+	}
+
+	public function ExpressionsWithObjectFieldsProvider()
+	{
+		return array(
+			array('Location', array('name' => 'Grenoble', 'org_id' => 2), 'org_id', 2),
+			array('Location', array('name' => 'Grenoble', 'org_id' => 2), 'CONCAT(SUBSTR(name, 4), " cause")', 'noble cause'),
+		);
+	}
+
+	/**
+	 * @dataProvider ExpressionWithParametersProvider
+	 *
+	 * @param $sExpression
+	 * @param $aParameters
+	 * @param $expected
+	 *
+	 * @throws \OQLException
+	 * @throws \Exception
+	 */
+	public function testExpressionWithParameters($sExpression, $aParameters, $expected)
+	{
+		$oExpression = Expression::FromOQL($sExpression);
+		$res = $oExpression->Evaluate($aParameters);
+		static::assertEquals($expected, $res);
+	}
+
+	public function ExpressionWithParametersProvider()
+	{
+		return array(
+			array('CONCAT(SUBSTR(name, 4), " cause")', array('name' => 'noble'), 'le cause'),
+		);
+	}
+
+	/**
+	 * Check Expression::IfTrue
+	 *
+	 * @covers       Expression::FromOQL
+	 * @covers       Expression::IsTrue
+	 * @dataProvider TrueExpressionsProvider
+	 *
+	 * @param $sExpression
+	 * @param $bExpectTrue
+	 *
+	 * @throws \OQLException
+	 */
+	public function testTrueExpressions($sExpression, $bExpectTrue)
+	{
+		$oExpression = Expression::FromOQL($sExpression);
+
+		$res = $oExpression->IsTrue();
+		if ($bExpectTrue)
+		{
+			static::assertTrue($res, 'arg: '.$sExpression);
+		}
+		else
+		{
+			static::assertFalse($res, 'arg: '.$sExpression);
+		}
+	}
+
+	public function TrueExpressionsProvider()
+	{
+		$aExpressions = array(
+			array('1', true),
+			array('0 OR 0', false),
+			array('1 AND 1', true),
+			array('1 AND (1 OR 0)', true)
+		);
+		// Build a comprehensive index
+		$aRet = array();
+		foreach ($aExpressions as $aExp)
+		{
+			$aRet[$aExp[0]] = $aExp;
+		}
+		return $aRet;
+	}
+
+	/**
+	 * @covers       FunctionExpression::Evaluate()
+	 * @dataProvider TimeFormatsProvider
+	 *
+	 * @param $sFormat
+	 * @param $bProcessed
+	 * @param $sValueOrException
+	 *
+	 * @throws \CoreException
+	 * @throws \MySQLException
+	 * @throws \MySQLQueryHasNoResultException
+	 * @throws \Exception
+	 */
+	public function testTimeFormat($sFormat, $bProcessed, $sValueOrException)
+	{
+		$sDate = '2009-06-04 21:23:24';
+		$oExpression = new FunctionExpression('DATE_FORMAT', array(new ScalarExpression($sDate), new ScalarExpression("%$sFormat")));
+		if ($bProcessed)
+		{
+			$sqlValue = CMDBSource::QueryToScalar("SELECT DATE_FORMAT('$sDate', '%$sFormat')");
+			static::assertEquals($sqlValue, $sValueOrException, 'Check test against MySQL');
+
+			$res = $oExpression->Evaluate(array());
+			static::assertEquals($sValueOrException, $res, 'Check evaluation');
+		}
+		else
+		{
+			static::expectException($sValueOrException);
+			$oExpression->Evaluate(array());
+		}
+	}
+
+	public function TimeFormatsProvider()
+	{
+		$aTests = array(
+			array('a', true, 'Thu'),
+			array('b', true, 'Jun'),
+			array('c', true, '6'),
+			array('D', true, '4th'),
+			array('d', true, '04'),
+			array('e', true, '4'),
+			array('f', false, 'NotYetEvaluatedExpression'), // microseconds: no way!
+			array('H', true, '21'),
+			array('h', true, '09'),
+			array('I', true, '09'),
+			array('i', true, '23'),
+			array('j', true, '155'), // day of the year
+			array('k', true, '21'),
+			array('l', true, '9'),
+			array('M', true, 'June'),
+			array('m', true, '06'),
+			array('p', true, 'PM'),
+			array('r', true, '09:23:24 PM'),
+			array('S', true, '24'),
+			array('s', true, '24'),
+			array('T', true, '21:23:24'),
+			array('U', false, 'NotYetEvaluatedExpression'), // Week sunday based (mode 0)
+			array('u', false, 'NotYetEvaluatedExpression'), // Week monday based (mode 1)
+			array('V', false, 'NotYetEvaluatedExpression'), // Week sunday based (mode 2)
+			array('v', true, '23'), // Week monday based (mode 3 - ISO-8601)
+			array('W', true, 'Thursday'),
+			array('w', true, '4'),
+			array('X', false, 'NotYetEvaluatedExpression'),
+			array('x', true, '2009'), // to be used with %v (ISO - 8601)
+			array('Y', true, '2009'),
+			array('y', true, '09'),
+		);
+		$aRes = array();
+		foreach ($aTests as $aTest)
+		{
+			$aRes["Format %{$aTest[0]}"] = $aTest;
+		}
+		return $aRes;
+	}
+
+	/**
+	 * Systematically check all supported format specs, for a given date
+	 *
+	 * @covers       FunctionExpression::Evaluate()
+	 * @dataProvider EveryTimeFormatProvider
+	 *
+	 * @param $sDate
+	 *
+	 * @throws \CoreException
+	 * @throws \MySQLException
+	 * @throws \Exception
+	 */
+	public function testEveryTimeFormat($sDate)
+	{
+		$aFormats = $this->TimeFormatsProvider();
+		$aSelects = array();
+		foreach ($aFormats as $sFormatDesc => $aFormatSpec)
+		{
+			$sFormat = $aFormatSpec[0];
+			$bProcessed = $aFormatSpec[1];
+			if ($bProcessed)
+			{
+				$aSelects["%$sFormat"] = "DATE_FORMAT('$sDate', '%$sFormat') AS `$sFormat`";
+			}
+		}
+		$sSelects = "SELECT ".implode(', ', $aSelects);
+		$aRes = CMDBSource::QueryToArray($sSelects);
+		$aRow = $aRes[0];
+		foreach ($aFormats as $sFormatDesc => $aFormatSpec)
+		{
+			$sFormat = $aFormatSpec[0];
+			$bProcessed = $aFormatSpec[1];
+			if ($bProcessed)
+			{
+				$oExpression = new FunctionExpression('DATE_FORMAT', array(new ScalarExpression($sDate), new ScalarExpression("%$sFormat")));
+				$res = $oExpression->Evaluate(array());
+				static::assertEquals($aRow[$sFormat], $res, "Format %$sFormat not matching MySQL for '$sDate'");
+			}
+		}
+	}
+	public function EveryTimeFormatProvider()
+	{
+		return array(
+			array('1971-07-19 8:40:00'),
+			array('1999-12-31 23:59:59'),
+			array('2000-01-01 00:00:00'),
+			array('2009-06-04 21:23:24'),
+			array('2020-02-29 23:59:59'),
+			array('2030-10-21 23:59:59'),
+			array('2050-12-21 23:59:59'),
+		);
+	}
+
+	/**
+	 * Systematically check all supported format specs, for a range of dates
+	 *
+	 * @covers       FunctionExpression::Evaluate()
+	 * @dataProvider EveryTimeFormatOnDateRangeProvider
+	 *
+	 * @param $sStartDate
+	 * @param $sInterval
+	 * @param $iRepeat
+	 *
+	 * @throws \CoreException
+	 * @throws \MySQLException
+	 * @throws \Exception
+	 */
+	public function testEveryTimeFormatOnDateRange($sStartDate, $sInterval, $iRepeat)
+	{
+		$oDate = new DateTime($sStartDate);
+		for ($i = 0 ; $i < $iRepeat ; $i++)
+		{
+			$sDate = date_format($oDate, 'Y-m-d, H:i:s');
+			$this->debug("Checking '$sDate'");
+			$this->testEveryTimeFormat($sDate);
+			$oDate->add(new DateInterval($sInterval));
+		}
+	}
+
+	public function EveryTimeFormatOnDateRangeProvider()
+	{
+		return array(
+			'10 years, day by day' => array('2000-01-01', 'P1D', 365 * 10),
+			'1 day, hour by hour' => array('2000-01-01 00:01:02', 'PT1H', 24),
+			'1 hour, minute by minute' => array('2000-01-01 00:01:02', 'PT1M', 60),
+			'1 minute, second by second' => array('2000-01-01 00:01:02', 'PT1S', 60),
+		);
+	}
+}
--- a/test/core/MetaModelTest.php
+++ b/test/core/MetaModelTest.php
@@ -83,4 +83,100 @@ class MetaModelTest extends ItopDataTestCase
            ),
 		);
 	}
+
+	/**
+	 * @covers       MetaModel::GetDependentAttributes()
+	 * @dataProvider GetDependentAttributesProvider
+	 *
+	 * @param string $sClass
+	 * @param string $sAttCode
+	 * @param array $aExpectedAttCodes
+	 *
+	 * @throws \Exception
+	 */
+	public function testGetDependentAttributes($sClass, $sAttCode, array $aExpectedAttCodes)
+	{
+		$aRes = MetaModel::GetDependentAttributes($sClass, $sAttCode);
+		// The order doesn't matter
+		sort($aRes);
+		sort($aExpectedAttCodes);
+		static::assertEquals($aExpectedAttCodes, $aRes);
+	}
+
+	public function GetDependentAttributesProvider()
+	{
+		$aRawCases = array(
+			array('Person', 'org_id', array('location_id', 'org_name', 'org_id_friendlyname', 'org_id_obsolescence_flag')),
+			array('Person', 'name', array('friendlyname')),
+			array('Person', 'status', array('obsolescence_flag')),
+		);
+		$aRet = array();
+		foreach ($aRawCases as $i => $aData)
+		{
+			$aRet[$aData[0].'::'.$aData[1]] = $aData;
+		}
+		return $aRet;
+	}
+
+	/**
+	 * @covers       MetaModel::GetPrerequisiteAttributes()
+	 * @dataProvider GetPrerequisiteAttributesProvider
+	 *
+	 * @param string $sClass
+	 * @param string $sAttCode
+	 * @param array $aExpectedAttCodes
+	 *
+	 * @throws \Exception
+	 */
+	public function testGetPrerequisiteAttributes($sClass, $sAttCode, array $aExpectedAttCodes)
+	{
+		$aRes = MetaModel::GetPrerequisiteAttributes($sClass, $sAttCode);
+		// The order doesn't matter
+		sort($aRes);
+		sort($aExpectedAttCodes);
+		static::assertEquals($aRes, $aExpectedAttCodes);
+	}
+
+	public function GetPrerequisiteAttributesProvider()
+	{
+		$aRawCases = array(
+			array('Person', 'friendlyname', array('name', 'first_name')),
+			array('Person', 'obsolescence_flag', array('status')),
+			array('Person', 'org_id_friendlyname', array('org_id')),
+			array('Person', 'org_id', array()),
+			array('Person', 'org_name', array('org_id')),
+		);
+		$aRet = array();
+		foreach ($aRawCases as $i => $aData)
+		{
+			$aRet[$aData[0].'::'.$aData[1]] = $aData;
+		}
+		return $aRet;
+	}
+
+	/**
+	 * To be removed as soon as the dependencies on external fields are obsoleted
+	 * @Group Integration
+	 */
+	public function testManualVersusAutomaticDependenciesOnExtKeys()
+	{
+		foreach (\MetaModel::GetClasses() as $sClass)
+		{
+			if (\MetaModel::IsAbstract($sClass)) continue;
+
+			foreach (\MetaModel::ListAttributeDefs($sClass) as $sAttCode => $oAttDef)
+			{
+				if (\MetaModel::GetAttributeOrigin($sClass, $sAttCode) != $sClass) continue;
+				if (!$oAttDef instanceof \AttributeExternalKey) continue;
+
+				$aManual = $oAttDef->Get('depends_on');
+				$aAuto = \MetaModel::GetPrerequisiteAttributes($sClass, $sAttCode);
+				// The order doesn't matter
+				sort($aAuto);
+				sort($aManual);
+				static::assertEquals($aManual, $aAuto, "Class: $sClass, Attribute: $sAttCode");
+			}
+		}
+	}
+
 }