protected override Expression VisitSelect(SelectExpression select)
{
if (select.From != null && select.From.NodeType == (ExpressionType)DbExpressionType.Table)
{
var table = (TableExpression)select.From;
var expressions = GlobalQueryPolicy.GetPolicies(table.Type);
if (expressions.IsNullOrEmpty())
{
return(select);
}
var columns = select.Columns;
var where = select.Where;
foreach (var exp in expressions)
{
where = PolicyConditionReplacer.Replace(where, exp, columns);
}
return(select.Update(select.From, where, select.OrderBy, select.GroupBy, select.Skip, select.Take,
select.Segment, select.IsDistinct, select.Columns, select.Having, select.IsReverse));
}
else if (select.From != null)
{
var from = base.Visit(select.From);
return(select.Update(from, select.Where, select.OrderBy, select.GroupBy, select.Skip, select.Take,
select.Segment, select.IsDistinct, select.Columns, select.Having, select.IsReverse));
}
return(select);
}
public static Expression Replace(Expression where, Expression expression, IEnumerable <ColumnDeclaration> columns)
{
var visitor = new PolicyConditionReplacer {
_where = where, _columns = columns
};
visitor.Visit(PartialEvaluator.Eval(expression));
return(visitor._where);
}
