private TranslateResult Translate(Expression expression)
{
var projection = expression as ProjectionExpression;
var subQuery = expression as SubQueryProjection;
var groupQuery = expression as GroupingProjection;
if (groupQuery != null)
{
throw new TabularException("Can't Return groups from group by you must use aggregates, or retrieve the complete table and run groupng in Linq to objects");
////var query = new TabularGroupByRewriter(groupQuery).Rewrite();
////return Translate(query);
}
if (subQuery != null)
{
projection = subQuery.Projection;
}
expression = TabularEvaluator.PartialEval(expression);
var binder = new TabularQueryBinder(this);
var boundExpression = binder.Bind(expression);
var orders = binder.OrderByColumns;
if (projection == null && subQuery == null)
{
if (boundExpression is ProjectionExpression)
{
projection = (ProjectionExpression)boundExpression;
}
else
{
return(Translate(boundExpression));
}
}
if (projection == null)
{
throw new TabularException("Could not translate");
}
string commandText = new TabularQueryFormatter().Format(projection.Source, orders);
LambdaExpression projector = new ProjectionBuilder().Build(projection.Projector);
return
(new TranslateResult
{
CommandText = commandText,
Projector = projector
});
}
protected override Expression VisitConstant(ConstantExpression node)
{
//return base.VisitConstant(node);
var v = node.Value;
var keys = _memberMapping.Keys.ToList();
foreach (var member in keys)
{
var m = v.GetType().GetMember(member.Name).FirstOrDefault();
if (m != null && m.ReflectedType == member.ReflectedType)
{
var accessor = TabularEvaluator.PartialEval(Expression.MakeMemberAccess(node, m));
var t1 = _memberMapping[member].Item1;
_memberMapping[member] = new Tuple <Expression, Expression>(t1, accessor);
}
}
return(node);
}
