protected override DbExpression VisitConditionalExpression(DbConditionalExpression conditionalExpression)
{
string syntax = string.Format("CASE WHEN {0} THEN {1} ELSE {2} END", Visit(conditionalExpression.Condition),
Visit(conditionalExpression.IfTrue), Visit(conditionalExpression.IfFalse));
return ExpressionFactory.Sql(syntax);
}